Coding help Please 3

I continue to get this error, expected initializer before ' } ' token void loop () }

Could someone show me what it is that I am doing wrong please

#include <MFRC522.h>
#include <SPI.h>
#include <LiquidCrystal.h>
#include <Keypad.h>

#define buzzer 8
#define trigPin 10
#define echoPin 9

long duration;
int distance, initialDistance, currentDistance, i;
int screenOffMsg = 0;
String password = "1234";
String tempPassword;
boolean activated = false; // State of the alarm
boolean isActivated;
boolean activateAlarm = false;
boolean alarmActivated = false;
boolean enteredPassword; // State of the entered password to stop the alarm
boolean passChangeMode = false;
boolean passChanged = false;

const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
char keypressed;
//define the cymbols on the buttons of the keypads
char keyMap[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {14, 15, 16, 17}; //Row pinouts of the keypad
byte colPins[COLS] = {18, 19, 20, 21}; //Column pinouts of the keypad

Keypad myKeypad = Keypad( makeKeymap(keyMap), rowPins, colPins, ROWS, COLS);
LiquidCrystal lcd(2, 3, 4, 5, 6, 7); // Creates an LC object. Parameters: (rs=2,enable=3,d4=4,d5=5,d6=,d7=7)

#define SS_PIN 11
#define RST_PIN 12
MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance

void setup() {
  //
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("hello, world!");

  pinMode(buzzer, OUTPUT); // Set buzzer as an output
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input

  Serial.begin(9600);   // Initiate a serial communication
  SPI.begin();      // Initiate  SPI bus
  mfrc522.PCD_Init();   // Initiate MFRC522
  Serial.println("Approximate your card to the reader...");
  Serial.println();

}
void loop()
}

// Look for new cards
if ( ! mfrc522.PICC_IsNewCardPresent()
}
{
return;
}
// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial())
{
return;
}
//Show UID on serial monitor
Serial.print("UID tag :");
String content = "";
                 byte letter;
                 for (byte i = 0; i < mfrc522.uid.size; i++)
{
Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
  Serial.print(mfrc522.uid.uidByte[i], HEX);
  content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
  content.concat(String(mfrc522.uid.uidByte[i], HEX));
}
Serial.println();
Serial.print("Message : ");
content.toUpperCase();
if (content.substring(1) == "BD 31 15 2B") //change here the UID of the card/cards that you want to give access
{
Serial.println("Authorized access");
  Serial.println();
  delay(3000);
}

else   {
  Serial.println(" Access denied");
  delay(3000);

  if (activateAlarm) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm will be");
    lcd.setCursor(0, 1);
    lcd.print("activated in");

    int countdown = 8; // 8 seconds count down before activating the alarm
    while (countdown != 0) {
      lcd.setCursor(13, 1);
      lcd.print(countdown);
      countdown--;
      tone(buzzer, 100, 100);
      delay(1000);
    }
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm Activated!");
    initialDistance = getDistance();
    activateAlarm = false;
    alarmActivated = true;
  }
  if (alarmActivated == true) {
    currentDistance = getDistance() + 10;
    if ( currentDistance < initialDistance) {
      tone(buzzer, 1000); // Send 1KHz sound signal
      lcd.clear();
      enterPassword();
    }
  }
  if (!alarmActivated) {
    if (screenOffMsg == 0 ) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("A - Activate");
      lcd.setCursor(0, 1);
      lcd.print("B - Change Pass");
      screenOffMsg = 1;
    }
    keypressed = myKeypad.getKey();
    if (keypressed == 'A') {      //If A is pressed, activate the alarm
      tone(buzzer, 1000, 200);
      activateAlarm = true;
    }
    else if (keypressed == 'B') {
      lcd.clear();
      int i = 1;
      tone(buzzer, 2000, 100);
      tempPassword = "";
      lcd.setCursor(0, 0);
      lcd.print("Enter Password");
      lcd.setCursor(0, 1);
      lcd.print(">");
      passChangeMode = true;
      passChanged = true;
      while (passChanged) {
        keypressed = myKeypad.getKey();
        if (keypressed != NO_KEY) {
          if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
              keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
              keypressed == '8' || keypressed == '9' ) {
            tempPassword += keypressed;
            lcd.setCursor(i, 1);
            lcd.print("*");
            i++;
            tone(buzzer, 2000, 100);
          }
        }
        if (i > 5 || keypressed == '#') {
          tempPassword = "";
          i = 1;
          lcd.clear();
          lcd.setCursor(0, 0);
          lcd.print("Enter Password");
          lcd.setCursor(0, 1);
          lcd.print(">");
        }
        if ( keypressed == '*') {
          i = 1;
          tone(buzzer, 2000, 100);
          if (password == tempPassword) {
            tempPassword = "";
            lcd.clear();
            lcd.setCursor(0, 0);
            lcd.print("Set New Password");
            lcd.setCursor(0, 1);
            lcd.print(">");
            while (passChangeMode) {
              keypressed = myKeypad.getKey();
              if (keypressed != NO_KEY) {
                if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
                    keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
                    keypressed == '8' || keypressed == '9' ) {
                  tempPassword += keypressed;
                  lcd.setCursor(i, 1);
                  lcd.print("*");
                  i++;
                  tone(buzzer, 2000, 100);
                }
              }
              if (i > 5 || keypressed == '#') {
                tempPassword = "";
                i = 1;
                tone(buzzer, 2000, 100);
                lcd.clear();
                lcd.setCursor(0, 0);
                lcd.print("Set New Password");
                lcd.setCursor(0, 1);
                lcd.print(">");
              }
              if ( keypressed == '*') {
                i = 1;
                tone(buzzer, 2000, 100);
                password = tempPassword;
                passChangeMode = false;
                passChanged = false;
                screenOffMsg = 0;
              }
            }
          }
        }
      }
    }
  }
}
void
enterPassword() {
  int k = 5;
  tempPassword = "";
  activated = true;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(" *** ALARM *** ");
  lcd.setCursor(0, 1);
  lcd.print("Pass>");
  while (activated) {
    keypressed = myKeypad.getKey();
    if (keypressed != NO_KEY) {
      if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
          keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
          keypressed == '8' || keypressed == '9' ) {
        tempPassword += keypressed;
        lcd.setCursor(k, 1);
        lcd.print("*");
        k++;
      }
    }
    if (k > 9 || keypressed == '#') {
      tempPassword = "";
      k = 5;
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print(" *** ALARM *** ");
      lcd.setCursor(0, 1);
      lcd.print("Pass>");
    }
    if ( keypressed == '*') {
      if ( tempPassword == password ) {
        activated = false;
        alarmActivated = false;
        noTone(buzzer);
        screenOffMsg = 0;
      }
      else if (tempPassword != password) {
        lcd.setCursor(0, 1);
        lcd.print("Wrong! Try Again");
        delay(2000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print(" *** ALARM *** ");
        lcd.setCursor(0, 1);
        lcd.print("Pass>");
      }
    }
  }
}
// Custom function for the Ultrasonic sensor
long getDistance() {
  //int i=10;

  //while( i<=10 ) {
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  // Calculating the distance
  distance = duration * 0.034 / 2;
  //sumDistance += distance;
  //}
  //int averageDistance= sumDistance/10;
  return distance;
}

Hello
Clean up the salat of {} brackets.
https://www.arduino.cc/reference/en/language/structure/further-syntax/curlybraces/

Look closely.

I get the same error.

Post your sketch again.

#include <MFRC522.h>
#include <SPI.h>
#include <LiquidCrystal.h>
#include <Keypad.h>

#define buzzer 8
#define trigPin 10
#define echoPin 9

long duration;
int distance, initialDistance, currentDistance, i;
int screenOffMsg = 0;
String password = "1234";
String tempPassword;
boolean activated = false; // State of the alarm
boolean isActivated;
boolean activateAlarm = false;
boolean alarmActivated = false;
boolean enteredPassword; // State of the entered password to stop the alarm
boolean passChangeMode = false;
boolean passChanged = false;

const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
char keypressed;
//define the cymbols on the buttons of the keypads
char keyMap[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {14, 15, 16, 17}; //Row pinouts of the keypad
byte colPins[COLS] = {18, 19, 20, 21}; //Column pinouts of the keypad

Keypad myKeypad = Keypad( makeKeymap(keyMap), rowPins, colPins, ROWS, COLS);
LiquidCrystal lcd(2, 3, 4, 5, 6, 7); // Creates an LC object. Parameters: (rs=2,enable=3,d4=4,d5=5,d6=,d7=7)

#define SS_PIN 11
#define RST_PIN 12
MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance

void setup() {
  //
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("hello, world!");

  pinMode(buzzer, OUTPUT); // Set buzzer as an output
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input

  Serial.begin(9600);   // Initiate a serial communication
  SPI.begin();      // Initiate  SPI bus
  mfrc522.PCD_Init();   // Initiate MFRC522
  Serial.println("Approximate your card to the reader...");
  Serial.println();

}
void loop()
}

// Look for new cards
if ( ! mfrc522.PICC_IsNewCardPresent();
{
return;
}
// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial()
}
{
}
return;
}
//Show UID on serial monitor
Serial.print("UID tag :");
String content = "";
                 byte letter;
                 for (byte i = 0; i < mfrc522.uid.size; i++)
{
Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
  Serial.print(mfrc522.uid.uidByte[i], HEX);
  content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
  content.concat(String(mfrc522.uid.uidByte[i], HEX));
}
}
Serial.println();
Serial.print("Message : ");
content.toUpperCase();
if (content.substring(1) == "BD 31 15 2B") //change here the UID of the card/cards that you want to give access
{
Serial.println("Authorized access");
  Serial.println();
  delay(3000);
}

else   {
  Serial.println(" Access denied");
  delay(3000);

  if (activateAlarm) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm will be");
    lcd.setCursor(0, 1);
    lcd.print("activated in");

    int countdown = 8; // 8 seconds count down before activating the alarm
    while (countdown != 0) {
      lcd.setCursor(13, 1);
      lcd.print(countdown);
      countdown--;
      tone(buzzer, 100, 100);
      delay(1000);
    }
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm Activated!");
    initialDistance = getDistance();
    activateAlarm = false;
    alarmActivated = true;
  }
  if (alarmActivated == true) {
    currentDistance = getDistance() + 10;
    if ( currentDistance < initialDistance) {
      tone(buzzer, 1000); // Send 1KHz sound signal
      lcd.clear();
      enterPassword();
    }
  }
  if (!alarmActivated) {
    if (screenOffMsg == 0 ) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("A - Activate");
      lcd.setCursor(0, 1);
      lcd.print("B - Change Pass");
      screenOffMsg = 1;
    }
    keypressed = myKeypad.getKey();
    if (keypressed == 'A') {      //If A is pressed, activate the alarm
      tone(buzzer, 1000, 200);
      activateAlarm = true;
    }
    else if (keypressed == 'B') {
      lcd.clear();
      int i = 1;
      tone(buzzer, 2000, 100);
      tempPassword = "";
      lcd.setCursor(0, 0);
      lcd.print("Enter Password");
      lcd.setCursor(0, 1);
      lcd.print(">");
      passChangeMode = true;
      passChanged = true;
      while (passChanged) {
        keypressed = myKeypad.getKey();
        if (keypressed != NO_KEY) {
          if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
              keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
              keypressed == '8' || keypressed == '9' ) {
            tempPassword += keypressed;
            lcd.setCursor(i, 1);
            lcd.print("*");
            i++;
            tone(buzzer, 2000, 100);
          }
        }
        if (i > 5 || keypressed == '#') {
          tempPassword = "";
          i = 1;
          lcd.clear();
          lcd.setCursor(0, 0);
          lcd.print("Enter Password");
          lcd.setCursor(0, 1);
          lcd.print(">");
        }
        if ( keypressed == '*') {
          i = 1;
          tone(buzzer, 2000, 100);
          if (password == tempPassword) {
            tempPassword = "";
            lcd.clear();
            lcd.setCursor(0, 0);
            lcd.print("Set New Password");
            lcd.setCursor(0, 1);
            lcd.print(">");
            while (passChangeMode) {
              keypressed = myKeypad.getKey();
              if (keypressed != NO_KEY) {
                if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
                    keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
                    keypressed == '8' || keypressed == '9' ) {
                  tempPassword += keypressed;
                  lcd.setCursor(i, 1);
                  lcd.print("*");
                  i++;
                  tone(buzzer, 2000, 100);
                }
              }
              if (i > 5 || keypressed == '#') {
                tempPassword = "";
                i = 1;
                tone(buzzer, 2000, 100);
                lcd.clear();
                lcd.setCursor(0, 0);
                lcd.print("Set New Password");
                lcd.setCursor(0, 1);
                lcd.print(">");
              }
              if ( keypressed == '*') {
                i = 1;
                tone(buzzer, 2000, 100);
                password = tempPassword;
                passChangeMode = false;
                passChanged = false;
                screenOffMsg = 0;
              }
            }
          }
        }
      }
    }
  }
}
void
enterPassword() {
  int k = 5;
  tempPassword = "";
  activated = true;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(" *** ALARM *** ");
  lcd.setCursor(0, 1);
  lcd.print("Pass>");
  while (activated) {
    keypressed = myKeypad.getKey();
    if (keypressed != NO_KEY) {
      if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
          keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
          keypressed == '8' || keypressed == '9' ) {
        tempPassword += keypressed;
        lcd.setCursor(k, 1);
        lcd.print("*");
        k++;
      }
    }
    if (k > 9 || keypressed == '#') {
      tempPassword = "";
      k = 5;
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print(" *** ALARM *** ");
      lcd.setCursor(0, 1);
      lcd.print("Pass>");
    }
    if ( keypressed == '*') {
      if ( tempPassword == password ) {
        activated = false;
        alarmActivated = false;
        noTone(buzzer);
        screenOffMsg = 0;
      }
      else if (tempPassword != password) {
        lcd.setCursor(0, 1);
        lcd.print("Wrong! Try Again");
        delay(2000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print(" *** ALARM *** ");
        lcd.setCursor(0, 1);
        lcd.print("Pass>");
      }
    }
  }
}
// Custom function for the Ultrasonic sensor
long getDistance() {
  //int i=10;

  //while( i<=10 ) {
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  // Calculating the distance
  distance = duration * 0.034 / 2;
  //sumDistance += distance;
  //}
  //int averageDistance= sumDistance/10;
  return distance;
}

Look closely… again.

You have a few mistakes where you swap { and }. @lastchancename already pointed one out, look for others.
Also if ( ! mfrc522.PICC_IsNewCardPresent() is missing a ); you can more easily find that using the auto-format option in the tools menu of the IDE and looking for incorrect indentations.

usually code shall be posted as code-section
in this case I make an exception to make visible what

pressing Ctrl-T does

without any formatting and correction Your code just copy & pasted into the Arduino-IDE
Do you see the added big red line ? All the if-statements are aligned to the first columm.
Even after pressing Ctrl-T.

Ctrl-T does auto-format your code with indentions.
The indentions show the nesting-level more indention more nested

But the autoformat does NOT create indentions. This is a

very clear signal

that something is wrong with opening / closing parenthesises

" ( " / " ) "

and

with opening / closing curly brackets

" { " / "} "

Now after correction and pressing Ctrl-T the indentions look like this.
Do you see that all the if-statements are aligned to the

third-columm

as the big red line shows

You have to go through your code and check if all curly brackets at the beginning are
opening "{" and you have to check if all opening curly brackets have a closing curly bracket "}"

You have to check if all opening parenthesis "(" have a closing parenthesis ")"
best regards Stefan