Configuring Firebase GCM
Firebase allows you to send push notifications to Android devices.
You will need to configure a Firebase Project on Firebase
Once the project is created, tap the "Settings" Gear icon for the project and
Add Firebase to your Android App and enter the App Package ID and
Register the App
Once generated download the
google-services.json file, embed this in your project
Data for Push Notification Configuration in Rebar Hub
You will need the API Key, you obtain this through the Firebase Project Settings,
Cloud Messaging tab.
Server Key value from Firebase and use that as the
API Key in configuring
your Push Notifications for Android.