To add user:

WHM(root) -> Plugins -> RVglobalsoft Manager -> RVlogin Manager -> User Management -> Add User.

Add user to access to WHM (RVlogin) with Two-Factor Authentication.
To add user, you must have Google Authenticator application. Two-Factor Authentication will be required for WHM/SSH Root Access if it's enabled. If Two-Factor is disabled, RVlogin Single sign-on on WHM will be accessed by anyone who has root password.

The server access settings here will take effect to both WHM and SSH access.