This simple alarm clock doesnt trigger, can you help me?

Question

this is my alarm clock. The only problem with it that it does not trigger an alarm, not even when I have the app open, so I don't think the issue is with the backgroung procesing...

MainActivity:

  @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        alarmTimePicker = (TimePicker) findViewById(R.id.timePicker);
        alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);

    }

  
    public void OnToggleClicked(View view) {
        long time;
        if (((ToggleButton) view).isChecked()) {
            Toast.makeText(MainActivity.this, "ALARM ON", Toast.LENGTH_SHORT).show();
            Calendar calendar = Calendar.getInstance();

           
            calendar.set(Calendar.HOUR_OF_DAY, alarmTimePicker.getCurrentHour());
            calendar.set(Calendar.MINUTE, alarmTimePicker.getCurrentMinute());

         
            Intent intent = new Intent(this, AlarmReceiver.class);

           
            pendingIntent = PendingIntent.getBroadcast(this, 0, intent,  pendingIntent.FLAG_MUTABLE);

            time = (calendar.getTimeInMillis() - (calendar.getTimeInMillis() % 60000));
            if (System.currentTimeMillis() > time) {
                // setting time as AM and PM
                if (calendar.AM_PM == 0)
                    time = time + (1000 * 60 * 60 * 12);
                else
                    time = time + (1000 * 60 * 60 * 24);
            }
            
            alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, time, 10000, pendingIntent);
            // alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (time * 1000), pendingIntent);
        } else {
            alarmManager.cancel(pendingIntent);
            Toast.makeText(MainActivity.this, "ALARM off", Toast.LENGTH_SHORT).show();
        }
    }

AlarmReceiver:

public class AlarmReceiver extends BroadcastReceiver {
    @RequiresApi(api = Build.VERSION_CODES.Q)
    @Override

    public void onReceive(Context context, Intent intent) {


        Vibrator vibrator = (Vibrator) context.getSystemService(context.VIBRATOR_SERVICE);
        vibrator.vibrate(4000);

        Toast.makeText(context, "Alarm! Wake up! Wake up!", Toast.LENGTH_LONG).show();
        Uri alarmUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_ALARM);
        if (alarmUri == null) {
            alarmUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        }


        Ringtone ringtone = RingtoneManager.getRingtone(context, alarmUri);


        ringtone.play();
    }
}

Manifest:

uses-permission android:name="android.permission.VIBRATE"

Thanks for your help