Can not use the domain as it was not configured for this tenant

This error occurs if you try to add a PSTN gateway and your mycloudvoip.com.au domains have not been added correctly.

Possible issues:

• • Typo, go to Microsoft 365 Admin and check spelling of the 2 x domains
  • You have not added a temporary user using the mycloudvoip.com.au domain(s) as their default domain or default e-mail address
  • Microsoft is still processing (we have seen it take 1-2 hours)
  • We’ve sometimes needed to remove the temporary user and re-add again, make sure you add the temporary user with the mycloudvoip.com.au domain as its initial realm, not after the fact
  • As a last resort, we have sometimes needed to add the temporary users with full licenses such as E1,E2,E3 or Business Basic, Business Premium

How can I check? Using PowerShell

Get-CsTenant | fl Tenantid,Domain*

Double check that you see the two mycloudvoip.com.au domains listed under DomainUrlMap

TenantId : 04ff7c70-c62a-4299-xxxxx-xxxxxxxxxxxx 
Domains : {xxxxxxxxxx.tdr.mycloudvoip.com.au, yyyyyyyyyy.tdr-b.mycloudvoip.com.au, mydomain.com, mydomain.onmicrosoft.com} 
DomainUrlMap : {xxxxxxxxxx.tdr.mycloudvoip.com.au, yyyyyyyyyy.tdr-b.mycloudvoip.com.au, mydomain.com, mydomain.onmicrosoft.com}