HELP why is my code result not showing in my node-red dashboard!

[devinabe21]

#include <WiFi.h>
extern "C" {
  #include "freertos/FreeRTOS.h"
  #include "freertos/timers.h"
}
#include <AsyncMqttClient.h>

const int trig_pin = 25;
const int echo_pin = 26;

// Sound speed in air
#define SOUND_SPEED 340
#define TRIG_PULSE_DURATION_US 10


float ultrason_duration;
unsigned long distance_cm;

// Change the credentials below, so your ESP32 connects to your router
#define WIFI_SSID "TP-Link_BIOMED"
#define WIFI_PASSWORD "B!0medical"

// Change the MQTT_HOST variable to your Raspberry Pi IP address, 
// so it connects to your Mosquitto MQTT broker
#define MQTT_HOST IPAddress(192, 168, 0, 108)
#define MQTT_PORT 1883

// Create objects to handle MQTT client
AsyncMqttClient mqttClient;
TimerHandle_t mqttReconnectTimer;
TimerHandle_t wifiReconnectTimer;

   // Stores last time height was published
const long interval = 10000;         // interval at which to publish sensor readings

const int ledPin = 25;              // GPIO where the LED is connected to
int ledState = LOW;                 // the current state of the output pin

// GPIO where the DS18B20 is connected to
const int oneWireBus = 27;          
// Setup a oneWire instance to communicate with any OneWire devices


const int buttonPin = 32;            // Define GPIO where the pushbutton is connected
int buttonState;                     // current reading from the input pin (pushbutton)
int lastButtonState = LOW;           // previous reading from the input pin (pushbutton)
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 50;    // the debounce time; increase if the output flicker

void connectToWifi() {
  Serial.println("Connecting to Wi-Fi...");
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
}

void connectToMqtt() {
  Serial.println("Connecting to MQTT...");
  mqttClient.connect();
}

void WiFiEvent(WiFiEvent_t event) {
  Serial.printf("[WiFi-event] event: %d\n", event);
  switch(event) {
    case SYSTEM_EVENT_STA_GOT_IP:
      Serial.println("WiFi connected");
      Serial.println("IP address: ");
      Serial.println(WiFi.localIP());
      connectToMqtt();
      break;
    case SYSTEM_EVENT_STA_DISCONNECTED:
      Serial.println("WiFi lost connection");
      xTimerStop(mqttReconnectTimer, 0); // ensure we don't reconnect to MQTT while reconnecting to Wi-Fi
      xTimerStart(wifiReconnectTimer, 0);
      break;
  }
}

// Add more topics that want your ESP32 to be subscribed to
void onMqttConnect(bool sessionPresent) {
  Serial.println("Connected to MQTT.");
  Serial.print("Session present: ");
  Serial.println(sessionPresent);
  // ESP32 subscribed to esp32/bodyTemp topic
  uint16_t packetIdSub = mqttClient.subscribe("esp32/marcell", 0);
  Serial.print("Subscribing at QoS 0, packetId: ");
  Serial.println(packetIdSub);
}

void onMqttDisconnect(AsyncMqttClientDisconnectReason reason) {
  Serial.println("Disconnected from MQTT.");
  if (WiFi.isConnected()) {
    xTimerStart(mqttReconnectTimer, 0);
  }
}

void onMqttSubscribe(uint16_t packetId, uint8_t qos) {
  Serial.println("Subscribe acknowledged.");
  Serial.print("  packetId: ");
  Serial.println(packetId);
  Serial.print("  qos: ");
  Serial.println(qos);
}

void onMqttUnsubscribe(uint16_t packetId) {
  Serial.println("Unsubscribe acknowledged.");
  Serial.print("  packetId: ");
  Serial.println(packetId);
}

void onMqttPublish(uint16_t packetId) {
  Serial.println("Publish acknowledged.");
  Serial.print("  packetId: ");
  Serial.println(packetId);
}

// You can modify this function to handle what happens when you receive a certain message in a specific topic
void onMqttMessage(char* topic, char* payload, AsyncMqttClientMessageProperties properties, size_t len, size_t index, size_t total) {
  String messageTemp;
  for (int i = 0; i < len; i++) {
    //Serial.print((char)payload[i]);
    messageTemp += (char)payload[i];
  }
  // Check if the MQTT message was received on topic esp32/bodyTemp
  if (strcmp(topic, "esp32/marcell") == 0) {
    // If the LED is off turn it on (and vice-versa)
    if (messageTemp == "on") {
      digitalWrite(ledPin, HIGH);
    } 
    else if (messageTemp == "off") {
      digitalWrite(ledPin, LOW);
    }
  }
 
  Serial.println("Publish received.");
  Serial.print("  message: ");
  Serial.println(distance_cm);
  Serial.print("  topic: ");
  Serial.println(topic);
  Serial.print("  qos: ");
  Serial.println(properties.qos);
  Serial.print("  dup: ");
  Serial.println(properties.dup);
  Serial.print("  retain: ");
  Serial.println(properties.retain);
  Serial.print("  len: ");
  Serial.println(len);
  Serial.print("  index: ");
  Serial.println(index);
  Serial.print("  total: ");
  Serial.println(total);
}



void setup() {
  // Start the DS18B20 sensor
  //sensors.begin();
  
  // Define LED as an OUTPUT and set it LOW
  pinMode(trig_pin, OUTPUT);
  digitalWrite(echo_pin, LOW);
  
  // Define buttonPin as an INPUT
  pinMode(buttonPin, INPUT);
  
  Serial.begin(115200);

  mqttReconnectTimer = xTimerCreate("mqttTimer", pdMS_TO_TICKS(2000), pdFALSE, (void*)0, reinterpret_cast<TimerCallbackFunction_t>(connectToMqtt));
  wifiReconnectTimer = xTimerCreate("wifiTimer", pdMS_TO_TICKS(2000), pdFALSE, (void*)0, reinterpret_cast<TimerCallbackFunction_t>(connectToWifi));

  WiFi.onEvent(WiFiEvent);

  mqttClient.onConnect(onMqttConnect);
  mqttClient.onDisconnect(onMqttDisconnect);
  mqttClient.onSubscribe(onMqttSubscribe);
  mqttClient.onUnsubscribe(onMqttUnsubscribe);
  mqttClient.onMessage(onMqttMessage);
  mqttClient.onPublish(onMqttPublish);
  mqttClient.setServer(MQTT_HOST, MQTT_PORT);

  connectToWifi();
}
int value = 0;
    
void loop() {
  // Set up the signal
  digitalWrite(trig_pin, LOW);
  delayMicroseconds(2);
 // Create a 10 µs impulse
  digitalWrite(trig_pin, HIGH);
  delayMicroseconds(TRIG_PULSE_DURATION_US);
  digitalWrite(trig_pin, LOW);

  // Return the wave propagation time (in µs)
  ultrason_duration = pulseIn(echo_pin, HIGH);

//distance calculation
  distance_cm = ultrason_duration * SOUND_SPEED/2 * 0.0001;

  // We print the distance on the serial port
  Serial.print("Distance (cm): ");
  Serial.println(distance_cm);

  // Read the state of the pushbutton and save it in a local variable
  int reading = digitalRead(buttonPin);

  // If the pushbutton state changed (due to noise or pressing it), reset the timer
  if (reading != lastButtonState) {
    // Reset the debouncing timer
    lastDebounceTime = millis();
  }

  delay(1000);
}