How to generate Firebase Keys and Identifiers JSON Configuration File?

Follow the steps below to create your Firebase JSON configuration file for setting up push notifications:

Go to Firebase Console and sign in with your Google account.
Select an existing project or create a new project.
Click the cogwheel icon next to Project Overview, then select Project settings.
Under the General tab in the Project Settings, scroll down to the “Your Apps” section. Select the web app for which the keys and identifiers need to be obtained.
Under SDK setup and configuration, choose the “Config” option. Click the copy icon to copy the configuration snippet to your clipboard.
Open any text editor (e.g., Sublime Text, Notepad). Paste the copied code into the editor.
Save the file with a ".json" extension (e.g., firebaseconfig.json).
Upload the created JSON file in the Push Notifications section.