This API call will return the profile of the actual authenticated user in the form of a MBAuthUser, which represents a registered user inside your project, you will find all the information you set in registration, with the “auxiliar_data” field as you sent through the Signup API .
If you call this method before a login you will receive an error because there is no user authenticated, so make sure a user is authenticated before calling this API (you can easily achieve this by calling MBCommonMethods.hasLoggedIn(applicationContext).