How to direct a user who registers through one plugin to wp simple membership?

Question

WordPress

Hello! the situation is this... There is a Login/Signup Popup plugin, a pop-up registration form. I need the user to register through it and get into the 'members' in the Wp Simple Membership plugin. Yes, there is also a form there, but it is not a popup. If you know an option how to turn it into what you need, please share.