arduino en bluetooth

hello i have a problem. :~
i want to communicate with my phone and arduino with bluetooth .
when i upload de sketch on de arduinobord then i can’t enter ‘z’ in my terminal (see code). I can enter ‘a’ .

#include <Time.h> 
#include <Wire.h> 
#include <DS1307RTC.h> 
#include <LiquidCrystal.h> 
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
const int switchPin = 6;
int switchState = 0;
int prevSwitchState = 0;
int reply;
char INBYTE;

void setup() {
  Serial.begin(9600);
 
 setSyncProvider(RTC.get);   
 if(timeStatus()!= timeSet)
 Serial.println("Unable to sync with the RTC");
 else
 Serial.println("RTC has set the system time"); 
 
 pinMode(10, OUTPUT);
}

void loop() {
  Serial.println("press a for time and z for the alarm ");
  while (!Serial.available()); 
  INBYTE = Serial.read();        
  if( INBYTE == 'a' )    digitalClockDisplay(); 
   delay(1000);
}

void digitalClockDisplay(){
  // digital clock display of the time
  Serial.print(hour());
  printDigits(minute());
  printDigits(second());
  Serial.print(" ");
  Serial.print(day());
  Serial.print(" ");
  Serial.print(month());
  Serial.print(" ");
  Serial.print(year());
  Serial.println();
 
lcd.setCursor(2, 0);                                            
lcd.print(hour());
lcd.print(":");
lcd.print (minute());
lcd.print(":");
lcd.print(second());
lcd.print(" ");
lcd.print("");
lcd.setCursor(3, 1);                                           // Set LCD cursor position (column,row) 
lcd.print(day());
lcd.print(".");
lcd.print(month());
lcd.print(".");
lcd.print(year());

// Print text to LCD
                                     // Delay to read text
                               // Clear the display

}

void printDigits(int digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  Serial.print(":");
  if(digits < 10)
    Serial.print('0');
  Serial.print(digits);
  
  
  if( INBYTE == 'z' ) switchState = digitalRead(switchPin);

    if (switchState != prevSwitchState) {
      if (switchState == LOW) {


        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print("! tsunami !");
        lcd.setCursor(4, 1);

        switch(reply) {
        case 0:
          lcd.print("go to");
          delay(3000);
        case 1:
          lcd.setCursor(3, 1);
          lcd.print("belfort");
          delay(3000);
        case 2:
          lcd.setCursor(3, 1);
          lcd.print("te Veurne ");
          delay(3000);
        }
      }
    }
    prevSwitchState = switchState;
  }

can you help me ?

Why don't you just add the code to handle a 'z'?
Or do you mean your terminal doesn't have a 'z' key?

de ‘z’ button is in the terminal.
i’m new in the arduinoworld .
would you help me ?

I can't figure out what you're trying to do.
INBYTE cannot be both 'z' and 'a'.

i want that if I press a in my terminal the time appear and when i press z in my therminal the text appear on the screen.

I don't understand why you've placed the 'z' handling code in "printDigits", where INBYTE cannot possibly be 'z' (as far as I can see).
Why not put the text handling stuff in a different function, and call that from "loop()" if INBTYTE is a 'z'?

I don't really understand function yet,.
Can you show me please the rood sketch.

I don't really understand function yet,

And yet "digitalClockDisplay" and "printDigits" are both functions.

I'm sorry, I don't know what "rood" is (apart from an archaic unit of measure)

Sorry i mean good