You can either use PowerShell or Command Prompt to add Azure AD users to remote desktop users’ groups. Both will do the same job. However, only the command differs.
If you prefer to use the command prompt, use the below command to add Azure AD users to the remote desktop users’ group.
net localgroup “Remote Desktop Users” /add “AzureAD\username@xyz.com”
[Note: Instead of username@xyz.com email address you need to use your domain email address]
If you want to use PowerShell to add the user to the remote desktop users’ group.
Add-LocalGroupMember -Group "Remote Desktop Users" -Member "AzureAD\username@domain.onmicrosoft.com"
[Note: Instead of username@xyz.com email address you need to use your domain email address]