Teams will soon allow you to transfer between a mobile device and a computer while in a meeting. Additionally, this function will allow you to add another device as a companion to your meeting. To switch and add devices in meetings, the devices must be logged in to Teams with the same UTA account using Azure Active Directory.
How to switch and add devices:
Open the Teams app on your second device
Select “Join” on the banner saying that a meeting is in progress.
Select “Add this device” or “Transfer to this device”