Can I assign group at Registration?

I am using s2Member to track paying members. UAM appears to integrate with it, but I was wondering if there is a way to assign new registrants to existing groups when they sign up. For example, I am setting up US State pages, and I want to restrict access to people from those states. s2Member modifies the registration page, so I can put Users into states when they register, AND I can restrict their access to the state and common pages, but shouldn’t there be a way to make the state unique identifier on the reg form correspond to the group they’re in?

https://www.ads-software.com/plugins/user-access-manager/