Mandatory User Attributes

Hi, I’m searching for a method to do this simple task:

  1. an user try to login in an application using keycloak (oidc standard flow)
  2. the user login using his credentials in the keycloak login form
  3. if the user has specific attributes (not properties, attributes), login process can continue
  4. else the user can compile a profile form to complete his data with expected attributes

I think that I can implement this process using custom authentication flow with conditional execution flow but I’m not sure if this is the correct way because it’s not easy and I’ve not any idea to show the form to complete non standard attibutes.

Can you help me?