Login to https://console.firebase.google.com a/c: xxx@gmail.com through gmail account
package name: com.xxx.firebase project name: MyFirstFirebase nick name of project is: Demo Firebase App
Click "register app" button
Download google-services.json file.
Create one android project with above package name.And paste the google-services.json in the porject's app folder.
Click "continue" button.
Sending Messages from Firebase Console.
Now we’ll send the first message from firebase console. Go to firebase console and click on Notifications in left menu. You will get an interface where you can type the message, select the targeting and send the message.