Registration form for two types of users customisation via SPI

I have a sample setup with angular, keycloak and spring boot.I need to acustom two major types of users - Customer and Professional. I am using Keycloaks login page to authenticate users and then dealing with the frontend via roles,attributes etc. The real issue comes at the time of registration - the different type of users have different fields that are additional information and are not related to authentication nor authorization. I need to somehow modify the registration flow to:

  1. Possibly duplicate the registration page for the type of user and redirect by some URL parameter. - I am aware that it is possible to use conditions in the forms and provide a dropdown for the user to chose their type- Its preferable to have 2 different pages.
  2. Assign a role or an attribute right after the registration to indicate what type of user has been registered.
  3. Store the additional information that does not need to be stored in keycloak in an external database.

I tried to find information on how to achieve this almost everywhere.I have a feeling that SPI has a lot modification options I find it very hard to believe that I am the only one struggling with this and that is not possible to be done using the SPI .

What will be the best approach to this issue and if there is any information to be found it will be very apreciated.

Also thank you for existing and for supporting Keycloak.