Notification does not come if I don't access the App

Question

Hi guys I have this problem, I have programmed an App send notifications via Firebase Cloud Messaging below the code:

package com.app.name.Service;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.graphics.Color;
import android.os.Build;
import android.provider.Settings;
import android.util.Log;

import androidx.annotation.NonNull;
import androidx.core.app.NotificationCompat;

import com.fourapper.forpaper.R;
import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;

import java.util.Map;
import java.util.Random;

public class MyFirebaseService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);

        if(remoteMessage.getData().isEmpty()){

            showNotification(remoteMessage.getNotification().getTitle(), remoteMessage.getNotification().getBody());

        }else{

            showNotification1(remoteMessage.getData());
        }

    }

    private void showNotification1(Map<String, String> data) {

        String title = data.get("title").toString();
        String body = data.get("body").toString();


        NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        String NOTIFICATION_CHANNEL_ID = "com.app.name.Test";

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID,"Notification", NotificationManager.IMPORTANCE_HIGH);

            notificationChannel.setDescription("Channel");
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.RED);
            notificationChannel.enableVibration(true);
            notificationChannel.setVibrationPattern(new long[]{ 0, 1000, 500,1000});
            notificationManager.createNotificationChannel(notificationChannel);
        }

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);
        notificationBuilder.setAutoCancel(true)
                .setDefaults(Notification.DEFAULT_ALL)
                .setWhen(System.currentTimeMillis())
                .setSmallIcon(R.drawable.ic_money_bag)
                .setVibrate(new long[]{500, 500})
                .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
                .setContentTitle(title)
                .setContentText(body)
                .setContentInfo("info");

        notificationManager.notify(new Random().nextInt(), notificationBuilder.build());
    }

    private void showNotification(String title, String body) {
        NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        String NOTIFICATION_CHANNEL_ID = "com.app.name.Test";

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID,"Notification", NotificationManager.IMPORTANCE_HIGH);

            notificationChannel.setDescription("Channel");
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.RED);
            notificationChannel.enableVibration(true);
            notificationChannel.setVibrationPattern(new long[]{ 0, 1000, 500,1000});
            notificationManager.createNotificationChannel(notificationChannel);
        }

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);
        notificationBuilder.setAutoCancel(true)
                .setDefaults(Notification.DEFAULT_ALL)
                .setWhen(System.currentTimeMillis())
                .setSmallIcon(R.drawable.ic_money_bag)
                .setVibrate(new long[]{500, 500})
                .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
                .setContentTitle(title)
                .setContentText(body)
                .setContentInfo("info");

        notificationManager.notify(new Random().nextInt(), notificationBuilder.build());
    }

    @Override
    public void onNewToken(@NonNull String s) {
        super.onNewToken(s);

        Log.d("TOKENFIREBASE", s);
    }
}

everything works only that I have encountered this problem, since I have scheduled the sending of a daily notification, I noticed that if I don't access the app in the day the notification is not sent to me, instead if I access the app in the day the notification it comes to me, I can't understand where the problem is, if you can help me thanks

Answer 1

below is the code of my manifest, as you can see I put everything in a Service class placed in a Service folder:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.app.name">

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.VIBRATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        android:usesCleartextTraffic="true"
        tools:targetApi="m">

        <!-- AdMob App ID: -->
        <meta-data
            android:name="com.google.android.gms.ads.APPLICATION_ID"
            android:value=""/>
        <meta-data
            android:name="preloaded_fonts"
            android:resource="@array/preloaded_fonts" />

        <activity android:name=".MainActivity">

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

        <service
            android:name=".Service.MyFirebaseService"
            tools:ignore="ExportedService,InnerclassSeparator">
            <intent-filter>
                <action android:name="com.google.firebase.MESSAGING_EVENT"/>
            </intent-filter>
        </service>

    </application>

</manifest>