Once you've created your app, a "Select how your app integrates with Facebook" section will appear. Specify the following callback URL as the Site URL under Website with Facebook Login or as the Secure Canvas URL under App on Facebook and save changes:
Run the InitializeOAuth choreo, specifying the App ID and App Secret from the app you registered at Facebook. The InitializeOAuth choreo will return an authorization URL and a callback ID (required for the FinalizeOAuth step).
Open a new web browser, navigate to the authorization URL returned by the InitializeOAuth choreo, and click "allow" to grant the app access to your Facebook account.
Run the FinalizeOAuth choreo, specifying the callback ID returned earlier by the InitializeOAuth choreo, to obtain an OAuth access token that can be used to access the Facebook API.