How to manually add users but allow them to input their username and password?

Hello,

We have an unusual set up where we need to be able to add users manually, but when they get the account activation email they link to a registration form to “finish setting up their account” including setting their username and password. How could I pull this off?

I created a page called “Create Your Account” with a Registration form that includes first name, last name, username, and password fields. I put the link to that page in the welcome email, but that doesn’t stop the general public from going to that URL and registering as a user. If I try to restrict access to that page, then new users don’t get to the registration form, instead they get the “Please login to view this content” message.

Ideally, as a customer you would get an email saying, “You have been added as a user, click here to create your account.” You would click the link and fill in your name and password. We only want people we’ve added ourselves to be able to register and complete their login credentials.

Any ideas? Thank you so much!