Identity Provider Custom User Attributes

The concept name was not provided (marked as "undefined"), and the supplied sources cover the User API Service and Specify Attributes in a New Role — neither of which can be confidently mapped to an unnamed concept. Based on the available sources, the closest supportable definition is:

The User API Service is an endpoint exposed by the application router that returns details of the users who are logged into an application. Developers use it to retrieve authenticated user information at runtime within SAP BTP applications. Administrators can complement user identity with role attributes to control access based on user-specific properties defined in roles.