We have recently refreshed our branding across our offerings and changed the names of our pricing plans. If you have signed up before Aug 9, 2021, please click Previous plans to view your applicable plans.
We assure you that this change will not impact your product experience, and no action is required on your part.

Please navigate to Admin -> Channels -> Portals -> Settings and choose the option "No" under Allow users to Sign Up from the customer portal

This would not allow users to sign up from the portal - you would have to send them an activation email to create an account with your system.