Create a Custom Facebook OAuth Web App

To obtain the OAuth client credentials, follow the steps below:

1. Log into Facebook and navigate to https://developers.facebook.com/apps.
2. Create a new app and click Settings > Basic. The OAuthClientId is the App Id displayed. The OAuthClientSecret is the App Secret.
3. Add a website platform on the Settings tab. Enter a Site URL. This value is not used in authentication. 

Follow the steps below to configure the OAuth redirect URI.

1. Go to your app settings and add the Facebook Login product from the Products section.
2. In the product settings, define the OAuth redirect URI.

   Set the redirect URI you want to be used as a callback URL, where the user will return with the token that verifies that they have granted your app access.