Kimberly, 

Thank you for your reply. Attempting to add users this way results in a message that they have already been invited and have an account, and that they simply need to login to GoPayment. Unfortunately, when they attempt to login they receive an error, and checking their permissions in QuickBooks online shows that they don't have GoPayment access.

Additionally, I did not see the Take Payment Only role you mentioned, but I did see a similar role called Associate.