Then, it has to be assigned to your’s and your coworkers’s email address.
The Trimble ID that buy’s the sub(s) get a seat automatically, and only when you log in with that Trimble ID, you get to distribute the seats.
check this:
https://www.design8.eu/en/sketchup-pro/821-signing-in-and-license-management-all-about-the-account-management-portal