Facebook OAuth requires you to fill in a Facebook App Id and Secret.
To enable Facebook OAuth on your workspace,
Login to your Facebook and navigate to My Apps.
Click on Create App. Select the app type from the list of options and Next.
Fill in the required details, then click Create App.
A dashboard with various app products is displayed. Click Set Up under Facebook Login.
Select Web as the platform for the app.
Go to Facebook Login > Settings page. Fill in the Valid OAuth Redirect URIs field with your workspace callback URL. Click Save Changes.
To view the OAuth credentials in your app, select Settings > Basic. Copy your App ID and App Secret.
Switch the App mode from Development to Live.
Navigate to OAuth settings (Administration > Workspace > Settings> OAuth) in your workspace.
In the Facebook tab, fill in the OAuth credentials you copied earlier and toggle on Facebook Login.
Click Save Changes. A Sign in with Facebook button appears on your workspace's login page. Users can now sign in with Facebook by clicking that button.