Updating user group

Hello @kolekin

– Allow the user to register an account with a specific user role

This is a basic functionality. With the Ultimate Member plugin you can create multiple registration forms. You can use a common role for all registrations or select a specific role for the certain registration form.
See doc A role for a new user.

It is also possible to add the “Roles” field to the registration form so that the user can select a role during registration.

– Allow an already registered user to change its user role with the form

Registered users can edit their profiles. You can add the “Roles” field to the profile form to allow users to change their role.

Important note about the “Roles” field: this field displays only custom user roles created with the Ultimate Member plugin and the predefined role “Subscriber”. Predefined user roles with high access permissions are hidden to avoid security issues. User roles created with third-party plugins are hidden to avoid conflicts.
See doc Configure role fields.

Regards