PushNotifications : MainActivity

MainActivity.java

package com.jayr.pushn;
 
import androidx.appcompat.app.AppCompatActivity;  
import android.os.Bundle; 
import android.widget.Toast; 
import com.google.android.gms.tasks.OnSuccessListener; 
import com.google.firebase.messaging.FirebaseMessaging;
 

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        FirebaseMessaging.getInstance().subscribeToTopic("ao")
                .addOnSuccessListener(new OnSuccessListener<Void>() {
            @Override
            public void onSuccess(Void aVoid) {
                Toast.makeText(getApplicationContext(),"Success",Toast.LENGTH_LONG).show();
            }
        });

    }

}