Username and password for a new person?

So I've just added a new person. They received a link to click on by email. They clicked on the linked, and it tells them something along of the lines that they are now able to receive notifications. OK, that's fine, but aren't they able to login to their own dashboard? Do you they to "Sign Up" to anturis independently of me adding them as a new user? How/where can I set a username + password for them?

Thanks,

Ross