@cjm_ms365 - did you get the correct license and get it working? I've been struggling for over a week with this and have a support ticket with Microsoft still going. It seems the only way to assign a phone number to the device is to also give the associated account a "domestic calling plan" license. I was under the impression the room license was an all-in-one bundle that included a few hundred minutes for dialing outbound. But without the domestic calling plan license, the phone has no functionality.