Enable Facebook Login

1. Open https://developers.facebook.com/apps/

2.i. Click Create App

2.ii. Select More Options > Something Else

1. Go to Settings> Basic 

2. Copy App ID, App Secret 

1. Open Firebase Console 

2. Go to Authentication> Sign in method> Facebook, then Press on Edit button (the pencil icon) 

1. Enable Facebook 

2. Paste APP ID and App secret 

3. Copy the OAuth redirect URI link 

1. Click on the Products "+" icon from the left panel and then click on Set Up button under Facebook Login card.

2. Go to PRODUCTS> Facebook Login for Gaming

3. Paste the OAuth Redirect URI 

Click on the "In development" Toggle Button to turn on "Live" Settings for your Facebook App.

NOTE: Other some other OAuth providers also have similar steps.