Не работает AlarmManager

intent = new Intent(this, NotificationSetter.class);
pendingIntent = PendingIntent.getBroadcast(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 5000, pendingIntent);

public class NotificationSetter extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Log.d("abc", "received");
        //setting a notification and doing smth else
    }
}

public class App extends Application {
 
    private static App mInstance;
 
    public App() {
        mInstance = this;
    }
 
    public static Context getAppContext() {
        return mInstance.getApplicationContext();
    }
 
...
 
}
 
// это было в сервисе
 
    private static final int NOTIFICATION_START_ID_1 = 1;
 
    public static void setAlarm(int cmd, long t) {
        Intent i = new Intent(App.getAppContext(), AlarmReceiver.class);
        i.putExtra("cmd", cmd);
        PendingIntent pi = PendingIntent.getBroadcast(App.getAppContext(), cmd, i, PendingIntent.FLAG_UPDATE_CURRENT);
        AlarmManager am = (AlarmManager) App.getAppContext().getSystemService(ALARM_SERVICE);
        if (Build.VERSION.SDK_INT >= 23) {// Wakes up the device in Doze Mode
            am.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, t, pi);
        } else if (Build.VERSION.SDK_INT >= 19) {// Wakes up the device in Idle Mode
            am.setExact(AlarmManager.RTC_WAKEUP, t, pi);
        } else {// Old APIs
            am.set(AlarmManager.RTC_WAKEUP, t, pi);
        }
    }
 
    private static Notification getNotification(String content, int id) {
        Context context = App.getAppContext();
        Intent resultIntent = new Intent(context, MainActivity.class);
 
        TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
        stackBuilder.addParentStack(MainActivity.class);
        stackBuilder.addNextIntent(resultIntent);
        PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(id, FLAG_UPDATE_CURRENT);
 
        NotificationCompat.Builder builder = new NotificationCompat.Builder(context)
                .setContentTitle(context.getString(R.string.app_name))
                .setContentText(content)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentIntent(resultPendingIntent)
                .setDefaults(Notification.DEFAULT_SOUND)
                .setAutoCancel(true);
        return builder.build();
    }
 
    public static void showNotification() {
        NotificationManager notificationManager = (NotificationManager) App.getAppContext().getSystemService(Service.NOTIFICATION_SERVICE);
        Notification notification = getNotification("Пришло время икс", NOTIFICATION_START_ID_1);
        notificationManager.notify(NOTIFICATION_START_ID_1, notification);
    }
 
// это в ресивере
 
public class AlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        int cmd = intent.getIntExtra("cmd", -1);
        if (cmd == 1) {
            showNotification();
        }
    }
}