Can’t change user wp role

Hi!
I use User Role Editor and Ultimate Member plugins.
I try to change role for new user on approve stage use this Ultimate Member hook:

add_action("um_after_user_is_approved","um_custom_after_user_is_approved");
function um_custom_after_user_is_approved( $user_id ){
   $role_slug = 'premium_member';
   UM()->roles()->set_role( $user_id, $role_slug );
}

But role doesn’t changed, were changed editional capabilities. The same issue with change WP role, changed only editional capbilities.
Could you please tell how to change wp role after user created in WP?

Thanks.
Best Regards.