Уведомление в определенное время с помощью BroadcastReceiver

Question

Я хочу сделать уведомление, которое звонит в 7 часов утра каждый день.
Но уведомление не работает

это MainActivity .java

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Toast;

import java.util.Calendar;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity{
AlarmManager alarm_manager;
Context context;
PendingIntent pendingIntent;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Calendar calendar;

    calendar = Calendar.getInstance();

    calendar.set(Calendar.HOUR_OF_DAY, 7);
    calendar.set(Calendar.MINUTE, 00);
    calendar.set(Calendar.SECOND, 00);

    final AlarmManager am = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(MainActivity.this, AlarmReceiver.class);
    final PendingIntent sender = PendingIntent.getBroadcast(MainActivity.this, 0, intent, 0);

    long TimeUntilTrigger;
    if (System.currentTimeMillis() > calendar.getTimeInMillis()) {
        TimeUntilTrigger = calendar.getTimeInMillis() + 86400000;
        Toast.makeText(getApplicationContext(), "past", Toast.LENGTH_LONG).show();
    } else {
        TimeUntilTrigger = calendar.getTimeInMillis();
        Toast.makeText(getApplicationContext(), "future", Toast.LENGTH_LONG).show();
    }
    am.setRepeating(AlarmManager.RTC_WAKEUP, TimeUntilTrigger, 24 * 60 * 60 * 1000, sender);
}
}

И это AlarmReceiver .java. Мне нужно использовать BroadcastReceiver, AppCompatActivity. Но это не может быть больше двух, чем я использовал "AppCompatActivity appCompatActivity" в этом предложении.

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.media.RingtoneManager;
import android.os.Build;
import android.os.Vibrator;
import android.util.Log;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.NotificationCompat;
import androidx.core.app.NotificationManagerCompat;

import static android.provider.Settings.System.getString;


public class AlarmReceiver extends BroadcastReceiver {
AppCompatActivity appCompatActivity;
    private final static int NOTICATION_ID = 222;

    public void onReceive(Context context, Intent intent) 

    {

        Toast.makeText(context,"It's time to start", Toast.LENGTH_SHORT).show();

        Vibrator vibrator = (Vibrator)context.getSystemService(Context.VIBRATOR_SERVICE);

        vibrator.vibrate(100);


        Log.d("AlarmBroadcastReceiver", "onReceive");


        String channelId = "channel";
        String channelName = "Channel Name";

        NotificationManager notifManager

                = (NotificationManager) appCompatActivity.getSystemService  (Context.NOTIFICATION_SERVICE);


        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {

            int importance = NotificationManager.IMPORTANCE_HIGH;

            NotificationChannel mChannel = new NotificationChannel(
                    channelId, channelName, importance);

            notifManager.createNotificationChannel(mChannel);

        }

        NotificationCompat.Builder builder =
                new NotificationCompat.Builder(appCompatActivity.getApplicationContext(), channelId);

        Intent notificationIntent = new Intent(appCompatActivity.getApplicationContext()

                , MainActivity.class);

        notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP |
                Intent.FLAG_ACTIVITY_SINGLE_TOP);

        int requestID = (int) System.currentTimeMillis();

        PendingIntent pendingIntent
                = PendingIntent.getActivity(appCompatActivity.getApplicationContext()

                , requestID

                , notificationIntent

                , PendingIntent.FLAG_UPDATE_CURRENT);

        builder.setContentTitle("Title") // required
                .setContentText("Content")  // required
                .setDefaults(Notification.DEFAULT_ALL) 
                .setAutoCancel(true) 

                .setSound(RingtoneManager

                        .getDefaultUri(RingtoneManager.TYPE_NOTIFICATION))

                .setSmallIcon(android.R.drawable.btn_star)
                .setContentIntent(pendingIntent);

        notifManager.notify(0, builder.build());



    }



}

Я могу 'Сплю из-за этого.(