Use PowerShell to assign a Teams phone number

To assign a Teams phone number using powershell you need to make sure the right licenses are added to the user, you can find the steps here: 

How to assign a Teams phone number to a user (zendesk.com)

After the license is assigned you can now use PowerShell to assign the phone number. 

1. Open PowerShell as an administrator
2. Connect to Teams module using: Connect-MicrosoftTeams
3. Run the following command, change  the user name, and add the phone number: Set-CsPhoneNumberAssignment -Identity "<User name>" -PhoneNumber <phone number> -PhoneNumberType DirectRouting
4. Hit Enter 

Allow a few minutes for the system to synchronize, after that the user should be able to use the new phone number assigned.