If you were being prompted for license on every start of Outlook, it may be possibly due to you not having ‘Owner’ rights over the Team Helpdesk folders (Ongoing Cases, Resolved Cases and Settings sub-folders). Only the user who has ‘Owner’ rights over these Team Helpdesk folders should perform the registration of the license. And only then the license would stick/saved to the folders field (and that would allow for Team Helpdesk to see the license automatically on every Outlook restart). Ideally, the user that has the manager add-in (and who did the first install of Team helpdesk) might have owner rights on the Team Helpdesk folders and he/she should perform the registration. And once successfully done, the license state should persists for all users.