Firebase Push Notification [duplicate]

This question already has an answer here:

Push notification works incorrectly when app is on background or not running 2 answers

I implemented Firebase for push notification in my Android app. I implemented two services for register the token and for create the notification when it is detected. When my app is launch it's working but when my app is closed it doesn't working.

public class FirebaseinstanceIdService extends FirebaseInstanceIdService {

    @Override
    public void onTokenRefresh() {
        String refreshedToken = FirebaseInstanceId.getInstance().getToken();
        Log.e("Firebase", refreshedToken);
        MainActivity.setFirebaseToken(refreshedToken);
    }

}

public class MyFirebaseMessageService extends FirebaseMessagingService {

    private static final String TAG = "MyFirebaseMsgService";

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        //Displaying data in log
        //It is optional
        Log.e(TAG, "From: " + remoteMessage.getFrom());
        Log.e(TAG, "Notification Message Body: " + remoteMessage.getData().get("title"));

        //Calling method to generate notification
        sendNotification(remoteMessage.getData());
    }

    //This method is only generating push notification
    //It is same as we did in earlier posts
    private void sendNotification(Map<String, String> notification) {
        Intent intent = new Intent(this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent,
            PendingIntent.FLAG_ONE_SHOT);

        Uri defaultSoundUri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
            .setSmallIcon(R.mipmap.ic_launcher)
            .setContentTitle(notification.get("title"))
            .setContentText(notification.get("body"))
            .setAutoCancel(true)
            .setSound(defaultSoundUri)
            .setContentIntent(pendingIntent);

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

        notificationManager.notify(0, notificationBuilder.build());
    }
}

And my manifest :

    <service
        android:name=".FirebaseinstanceIdService">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
        </intent-filter>
    </service>
    <service
        android:name=".MyFirebaseMessageService">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT"/>
        </intent-filter>
    </service>

And my request :

{
    "to": "ex1CtVz5bbE:APA91bHiM_BCun62A9iCobF1yV26Dwn-hYCDhkYPoWEG5ZdqH0P28UsE5q1v7QibwAX7AJ290-9en9L6f548_2b7WEbJ8RPEWlIotLczjjCP7xEOWqeJk6Iz44vilWYvdu4chPwfsvXD",
    "data": {
        "title": "Notification",
        "body": "Message",
    }
}

I already found a few solutions in StackOverflow but it doesn't work in my case. I have an API Rest which call the API Request Post : https://fcm.googleapis.com/fcm/send

So, there is my question : Does Firebase handle push notification when the app is closed and how to ?

Thank you for your answers

FCM does support notifications when app is closed. Your code seems to be OK, so I suppose battery economizers (or power savers) can kill your notifications. I had such problems on my Asus Zenfone, also they were reported in cases of using Huawei and Xiaomi. Just disable them or add your app in exception list, if there is one. Also there is a new power-saving mode in recent releases of Android, try to disable it too.