[keycloak-user] Make custom Mapper for a specific claim field with HTTP Service Call

Hi, I would like to add a specific claim field in the JWT Token, that take a value issued from a Service Call (HTTP POST that return a JSON result). I saw that I can maybe specify a custom Mapper with something like : public class PersonalMapper extends AbstractOIDCProtocolMapper implements OIDCAccessTokenMapper, OIDCIDTokenMapper, UserInfoTokenMapper{} But I don’t know where to use this code, and I don’t know where to call my Service in Keycloak. Maybe in a custom Provider ? The documentation is not really helpful since I don’t see any SPI for Custom Mapper, or a way to achieve this. Thanks for your help, Best Regards Vivien Brissat