The final step is to write a cloud function to listen for database activity. To start, make sure that you have installed the Firebase CLI and login.
$ npm install -g firebase-tools $ firebase login
Then cd into your project directory and run:
$ firebase init
When it prompts you to install node modules return yes. Once the script completes, in your React Native project you should now have a new folder: functions
Open < Firebase_functions_pushNotification_Script> and copy <index.js> and replace the <index.js> inside the functions folder created.
Then run the following commands:
$ cd /<yourprojectdirectory>/ $ firebase deploy
This uploads your function to Google’s servers.
And check the logs too for any activity: