[keycloak-user] Update user attributes on login

Hi, I have a running keycloak with a custom identity provider - corresponding implementation of AbstractOAuth2IdentityProvider On registration of a user certain user attributes are stored and mapped into the token. Now, I want to update these user attributes on following logins. How to do this? Unfortunately, I did not find a corresponding hint in the documentation. Thx in advance for your support. Best regards, Oliver