Supported entity types (e.g. registration)

Is the entity type "registration" supported?

Actually I get the error message

Call to a member function isAvailableForRegistration() on null" at ../web/modules/contrib/registration/src/Form/RegisterForm.php line 111"

when I ty to configure any of it´s fields inside Conditional Fields module (at admin/structure/conditional_fields/registration/[registration_type])

The entity type comes from module "Entity Registration" ( https://www.drupal.org/project/registration → ).

The Conditional fields module description, at the module page, says, in paragraph "dependencies":

But since it works on fields, some field and entity types need to be enabled.

Do I have to enable the registration entity type somewhere?

Thanks