How can I get Facebook access_token after the user has authenticated? I have tried to use the id_token to call to https://auth0.com/docs/api/management/v2#!/Users/get_users_by_id to get the access token, however, the ‘read:user_idp_tokens’ scope is not included in the token.
The id_token cannot be used to call the Management API. You will need to obtain a Management API access_token, and then call the Management API to obtain the idP’s access token. The following document outlines the step-by-step process to do this: