He can assign it to his account once he opens the dashboard on a computer within the same network like the A3 unit.

Basically, the computer he uses needs to have the same external IP like the A3 unit (to be in the same LAN). Then your friend will see the A3 in his Dashboard and be able to click the “ADD” button to assign it.

Let me know if you need any help. BTW, I just assigned both units to your account, so your friend might need to re-attach it in case he did previously.