Esp32 'class WebServer' has no member named 'available'

Hi! Total noobie here (copy and pasted a lot of stuff). I was trying to add a wifi credential setup page for one of my projects, But when I try to combine the code, an error shows up.

#include <WiFi.h>
#include <HTTPClient.h>
#include <WebServer.h>
#include <EEPROM.h>

//Variables
int i = 0;
int statusCode;
const char* ssid = "Default SSID";
const char* passphrase = "Default passord";
String st;
String content;
String esid;
String epass = "";
unsigned long previousMillis = 0;
unsigned long interval = 30000;
String header;
String output26State = "off";
String output27State = "off";
const int output26 = 26;
const int output27 = 27;
unsigned long currentTime = millis();
unsigned long previousTime = 0; 
const long timeoutTime = 2000;

//Function Decalration
bool testWifi(void);
void launchWeb(void);
void setupAP(void);

//Establishing Local server at port 80
WebServer server(80);

void setup()
{

  Serial.begin(115200); //Initialising if(DEBUG)Serial Monitor
  Serial.println();
  Serial.println("Disconnecting current wifi connection");
  WiFi.disconnect();
  EEPROM.begin(512); //Initialasing EEPROM
  delay(10);
  pinMode(15, INPUT);
  pinMode(output26, OUTPUT);
  pinMode(output27, OUTPUT);
  digitalWrite(output26, LOW);
  digitalWrite(output27, LOW);
  Serial.println();
  Serial.println();
  Serial.println("Startup");
  server.begin();

  //---------------------------------------- Read eeprom for ssid and pass
  Serial.println("Reading EEPROM ssid");


  for (int i = 0; i < 32; ++i)
  {
    esid += char(EEPROM.read(i));
  }
  Serial.println();
  Serial.print("SSID: ");
  Serial.println(esid);
  Serial.println("Reading EEPROM pass");

  for (int i = 32; i < 96; ++i)
  {
    epass += char(EEPROM.read(i));
  }
  Serial.print("PASS: ");
  Serial.println(epass);


  WiFi.begin(esid.c_str(), epass.c_str());
}

void loop() {
  WiFiClient client = server.available();   // Listen for incoming clients

  if (client) {                             // If a new client connects,
    currentTime = millis();
    previousTime = currentTime;
    Serial.println("New Client.");          // print a message out in the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    while (client.connected() && currentTime - previousTime <= timeoutTime) {  // loop while the client's connected
      currentTime = millis();
      if (client.available()) {             // if there's bytes to read from the client,
        char c = client.read();             // read a byte, then
        Serial.write(c);                    // print it out the serial monitor
        header += c;
        if (c == '\n') {                    // if the byte is a newline character
          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what's coming, then a blank line:
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println("Connection: close");
            client.println();
            
            // turns the GPIOs on and off
            if (header.indexOf("GET /26/on") >= 0) {
              Serial.println("GPIO 26 on");
              output26State = "on";
              digitalWrite(output26, HIGH);
            } else if (header.indexOf("GET /26/off") >= 0) {
              Serial.println("GPIO 26 off");
              output26State = "off";
              digitalWrite(output26, LOW);
            } else if (header.indexOf("GET /27/on") >= 0) {
              Serial.println("GPIO 27 on");
              output27State = "on";
              digitalWrite(output27, HIGH);
            } else if (header.indexOf("GET /27/off") >= 0) {
              Serial.println("GPIO 27 off");
              output27State = "off";
              digitalWrite(output27, LOW);
            }
            
            // Display the HTML web page
            client.println("<!DOCTYPE html><html>");
            client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
            client.println("<link rel=\"icon\" href=\"data:,\">");
            // CSS to style the on/off buttons 
            // Feel free to change the background-color and font-size attributes to fit your preferences
            client.println("<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}");
            client.println(".button { background-color: #4CAF50; border: none; color: white; padding: 16px 40px;");
            client.println("text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}");
            client.println(".button2 {background-color: #555555;}</style></head>");
            
            // Web Page Heading
            client.println("<body><h1>ESP32 Web Server</h1>");
            
            // Display current state, and ON/OFF buttons for GPIO 26  
            client.println("<p>GPIO 26 - State " + output26State + "</p>");
            // If the output26State is off, it displays the ON button       
            if (output26State=="off") {
              client.println("<p><a href=\"/26/on\"><button class=\"button\">ON</button></a></p>");
            } else {
              client.println("<p><a href=\"/26/off\"><button class=\"button button2\">OFF</button></a></p>");
            } 
               
            // Display current state, and ON/OFF buttons for GPIO 27  
            client.println("<p>GPIO 27 - State " + output27State + "</p>");
            // If the output27State is off, it displays the ON button       
            if (output27State=="off") {
              client.println("<p><a href=\"/27/on\"><button class=\"button\">ON</button></a></p>");
            } else {
              client.println("<p><a href=\"/27/off\"><button class=\"button button2\">OFF</button></a></p>");
            }
            client.println("</body></html>");
            
            // The HTTP response ends with another blank line
            client.println();
            // Break out of the while loop
            break;
          } else { // if you got a newline, then clear currentLine
            currentLine = "";
          }
        } else if (c != '\r') {  // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine
        }
      }
    }
    // Clear the header variable
    header = "";
    // Close the connection
    client.stop();
    Serial.println("Client disconnected.");
    Serial.println("");
  }
  unsigned long currentMillis = millis();
  // if WiFi is down, try reconnecting every CHECK_WIFI_TIME seconds
  if ((WiFi.status() != WL_CONNECTED) && (currentMillis - previousMillis >=interval)) {
    Serial.print(millis());
    Serial.println("Reconnecting to WiFi...");
    WiFi.disconnect();
    WiFi.reconnect();
    previousMillis = currentMillis;
  }

  if (testWifi() && (digitalRead(15) != 1))
  {
    Serial.println(" connection status positive");
    return;
  }
  else
  {
    Serial.println("Connection Status Negative / D15 HIGH");
    Serial.println("Turning the HotSpot On");
    launchWeb();
    setupAP();// Setup HotSpot
  }

  Serial.println();
  Serial.println("Waiting.");

  while ((WiFi.status() != WL_CONNECTED))
  {
    Serial.print(".");
    delay(100);
    server.handleClient();
  }
  delay(1000);
}


//----------------------------------------------- Fuctions used for WiFi credentials saving and connecting to it which you do not need to change
bool testWifi(void)
{
  int c = 0;
  //Serial.println("Waiting for Wifi to connect");
  while ( c < 20 ) {
    if (WiFi.status() == WL_CONNECTED)
    {
      return true;
    }
    delay(500);
    Serial.print("*");
    c++;
  }
  Serial.println("");
  Serial.println("Connect timed out, opening AP");
  return false;
}

void launchWeb()
{
  Serial.println("");
  if (WiFi.status() == WL_CONNECTED)
    Serial.println("WiFi connected");
  Serial.print("Local IP: ");
  Serial.println(WiFi.localIP());
  Serial.print("SoftAP IP: ");
  Serial.println(WiFi.softAPIP());
  createWebServer();
  // Start the server
  server.begin();
  Serial.println("Server started");
}

void setupAP(void)
{
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  delay(100);
  int n = WiFi.scanNetworks();
  Serial.println("scan done");
  if (n == 0)
    Serial.println("no networks found");
  else
  {
    Serial.print(n);
    Serial.println(" networks found");
    for (int i = 0; i < n; ++i)
    {
      // Print SSID and RSSI for each network found
      Serial.print(i + 1);
      Serial.print(": ");
      Serial.print(WiFi.SSID(i));
      Serial.print(" (");
      Serial.print(WiFi.RSSI(i));
      Serial.print(")");
      //Serial.println((WiFi.encryptionType(i) == ENC_TYPE_NONE) ? " " : "*");
      delay(10);
    }
  }
  Serial.println("");
  st = "<ol>";
  for (int i = 0; i < n; ++i)
  {
    // Print SSID and RSSI for each network found
    st += "<li>";
    st += WiFi.SSID(i);
    st += " (";
    st += WiFi.RSSI(i);

    st += ")";
    //st += (WiFi.encryptionType(i) == ENC_TYPE_NONE) ? " " : "*";
    st += "</li>";
  }
  st += "</ol>";
  delay(100);
  WiFi.softAP("ElectronicsInnovation", "");
  Serial.println("Initializing_softap_for_wifi credentials_modification");
  launchWeb();
  Serial.println("over");
}

void createWebServer()
{
  {
    server.on("/", []() {

      IPAddress ip = WiFi.softAPIP();
      String ipStr = String(ip[0]) + '.' + String(ip[1]) + '.' + String(ip[2]) + '.' + String(ip[3]);
      content = "<!DOCTYPE HTML>\r\n<html>Welcome to Wifi Credentials Update page";
      content += "<form action=\"/scan\" method=\"POST\"><input type=\"submit\" value=\"scan\"></form>";
      content += ipStr;
      content += "<p>";
      content += st;
      content += "</p><form method='get' action='setting'><label>SSID: </label><input name='ssid' length=32><input name='pass' length=64><input type='submit'></form>";
      content += "</html>";
      server.send(200, "text/html", content);
    });
    server.on("/scan", []() {
      //setupAP();
      IPAddress ip = WiFi.softAPIP();
      String ipStr = String(ip[0]) + '.' + String(ip[1]) + '.' + String(ip[2]) + '.' + String(ip[3]);

      content = "<!DOCTYPE HTML>\r\n<html>go back";
      server.send(200, "text/html", content);
    });

    server.on("/setting", []() {
      String qsid = server.arg("ssid");
      String qpass = server.arg("pass");
      if (qsid.length() > 0 && qpass.length() > 0) {
        Serial.println("clearing eeprom");
        for (int i = 0; i < 96; ++i) {
          EEPROM.write(i, 0);
        }
        Serial.println(qsid);
        Serial.println("");
        Serial.println(qpass);
        Serial.println("");

        Serial.println("writing eeprom ssid:");
        for (int i = 0; i < qsid.length(); ++i)
        {
          EEPROM.write(i, qsid[i]);
          Serial.print("Wrote: ");
          Serial.println(qsid[i]);
        }
        Serial.println("writing eeprom pass:");
        for (int i = 0; i < qpass.length(); ++i)
        {
          EEPROM.write(32 + i, qpass[i]);
          Serial.print("Wrote: ");
          Serial.println(qpass[i]);
        }
        EEPROM.commit();

        content = "{\"Success\":\"saved to eeprom... reset to boot into new wifi\"}";
        statusCode = 200;
        ESP.restart();
      } else {
        content = "{\"Error\":\"404 not found\"}";
        statusCode = 404;
        Serial.println("Sending 404");
      }
      server.sendHeader("Access-Control-Allow-Origin", "*");
      server.send(statusCode, "application/json", content);

    });
  }
}

Here is the original code, which was working.

// Load Wi-Fi library
#include <WiFi.h>

// Replace with your network credentials
const char* ssid = "WIFI";
const char* password = "PASSWORD";

unsigned long previousMillis = 0;
unsigned long interval = 30000;

// Set web server port number to 80
WiFiServer server(80);

// Variable to store the HTTP request
String header;

// Auxiliar variables to store the current output state
String output26State = "off";
String output27State = "off";

// Assign output variables to GPIO pins
const int output26 = 26;
const int output27 = 27;

// Current time
unsigned long currentTime = millis();
// Previous time
unsigned long previousTime = 0; 
// Define timeout time in milliseconds (example: 2000ms = 2s)
const long timeoutTime = 2000;

void initWiFi() {
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi ..");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print('.');
    delay(1000);
  }
  Serial.println(WiFi.localIP());
}


void setup() {
  Serial.begin(115200);

  initWiFi();
  Serial.print("RRSI: ");
  Serial.println(WiFi.RSSI());
  
  // Initialize the output variables as outputs
  pinMode(output26, OUTPUT);
  pinMode(output27, OUTPUT);
  // Set outputs to LOW
  digitalWrite(output26, LOW);
  digitalWrite(output27, LOW);

  // Connect to Wi-Fi network with SSID and password
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  // Print local IP address and start web server
  Serial.println("");
  Serial.println("WiFi connected.");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  server.begin();
}

void loop(){
  WiFiClient client = server.available();   // Listen for incoming clients

  if (client) {                             // If a new client connects,
    currentTime = millis();
    previousTime = currentTime;
    Serial.println("New Client.");          // print a message out in the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    while (client.connected() && currentTime - previousTime <= timeoutTime) {  // loop while the client's connected
      currentTime = millis();
      if (client.available()) {             // if there's bytes to read from the client,
        char c = client.read();             // read a byte, then
        Serial.write(c);                    // print it out the serial monitor
        header += c;
        if (c == '\n') {                    // if the byte is a newline character
          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what's coming, then a blank line:
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println("Connection: close");
            client.println();
            
            // turns the GPIOs on and off
            if (header.indexOf("GET /26/on") >= 0) {
              Serial.println("GPIO 26 on");
              output26State = "on";
              digitalWrite(output26, HIGH);
            } else if (header.indexOf("GET /26/off") >= 0) {
              Serial.println("GPIO 26 off");
              output26State = "off";
              digitalWrite(output26, LOW);
            } else if (header.indexOf("GET /27/on") >= 0) {
              Serial.println("GPIO 27 on");
              output27State = "on";
              digitalWrite(output27, HIGH);
            } else if (header.indexOf("GET /27/off") >= 0) {
              Serial.println("GPIO 27 off");
              output27State = "off";
              digitalWrite(output27, LOW);
            }
            
            // Display the HTML web page
            client.println("<!DOCTYPE html><html>");
            client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
            client.println("<link rel=\"icon\" href=\"data:,\">");
            // CSS to style the on/off buttons 
            // Feel free to change the background-color and font-size attributes to fit your preferences
            client.println("<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}");
            client.println(".button { background-color: #4CAF50; border: none; color: white; padding: 16px 40px;");
            client.println("text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}");
            client.println(".button2 {background-color: #555555;}</style></head>");
            
            // Web Page Heading
            client.println("<body><h1>ESP32 Web Server</h1>");
            
            // Display current state, and ON/OFF buttons for GPIO 26  
            client.println("<p>GPIO 26 - State " + output26State + "</p>");
            // If the output26State is off, it displays the ON button       
            if (output26State=="off") {
              client.println("<p><a href=\"/26/on\"><button class=\"button\">ON</button></a></p>");
            } else {
              client.println("<p><a href=\"/26/off\"><button class=\"button button2\">OFF</button></a></p>");
            } 
               
            // Display current state, and ON/OFF buttons for GPIO 27  
            client.println("<p>GPIO 27 - State " + output27State + "</p>");
            // If the output27State is off, it displays the ON button       
            if (output27State=="off") {
              client.println("<p><a href=\"/27/on\"><button class=\"button\">ON</button></a></p>");
            } else {
              client.println("<p><a href=\"/27/off\"><button class=\"button button2\">OFF</button></a></p>");
            }
            client.println("</body></html>");
            
            // The HTTP response ends with another blank line
            client.println();
            // Break out of the while loop
            break;
          } else { // if you got a newline, then clear currentLine
            currentLine = "";
          }
        } else if (c != '\r') {  // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine
        }
      }
    }
    // Clear the header variable
    header = "";
    // Close the connection
    client.stop();
    Serial.println("Client disconnected.");
    Serial.println("");
  }
  unsigned long currentMillis = millis();
  // if WiFi is down, try reconnecting every CHECK_WIFI_TIME seconds
  if ((WiFi.status() != WL_CONNECTED) && (currentMillis - previousMillis >=interval)) {
    Serial.print(millis());
    Serial.println("Reconnecting to WiFi...");
    WiFi.disconnect();
    WiFi.reconnect();
    previousMillis = currentMillis;
  }
}

Any help plz?

it should be WiFiServer server(80);

Got a different error with that
"class WIFIServer has no member named 'handleClient'"

so you have to decide if yo wan to use WebServer or WiFiServer .
your sketch is based on WiFiServer example so remove the part with handleClient.
or see the examples of the WebServer library

Understood, I will do just that, thank you very much!