NotificationManager notificationManager = (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "My Notifications", NotificationManager.IMPORTANCE_DEFAULT);
 
            // Configure the notification channel.
            notificationChannel.setDescription("Channel description");
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.RED);
            notificationChannel.setVibrationPattern(new long[]{0, 1000, 500, 1000});
            notificationChannel.enableVibration(true);
            notificationManager.createNotificationChannel(notificationChannel);
        }
 
        NotificationCompat.Builder builder = new NotificationCompat.Builder(MainActivity.context)
                .setVibrate(new long[]{0, 100, 100, 100, 100, 100})
                .setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION))
                .setSmallIcon(icon)
                .setContentTitle("Content Title")
                .setContentText("Content Text");
 
        notificationManager.notify(NOTIFY_ID, builder.build());

notificationManager.createNotificationChannel(notificationChannel);