As you may know, Teams can integrates with telephony system using Calling Plan.
While you can manage numbers using either the Teams administration portal or PowerShell, sometime delegating this management is not as easy as it should – especially when you want to delegate it by scoping location.
Well, good news you can now use this app developed by the Office teams to delegate PSTN phone numbers based on the location of the delegated admins/users.
NOTE Direct Routing is out of scope (for now?)