If you previously followed our article:
You may now find that you cannot access the Teams admin portal. If you are still using VIA UC Skype for Business, you will need to access the Teams admin portal using an appropriate admin on your .onmicrosoft.com domain. If you continue to follow this article and enable this again but are still using VIA UC Skype for Business, it is likely the below steps will break external federation for your Skype for Business users.
In a scenario where you have fully migrated from Skype for Business to Teams, you may still access the Teams admin portal with the .onmicrosoft.com domain, but it may be more appropriate long term to re-enable your usual domain in order you can access this with your usual admin accounts.
To achieve this, you will first need to download both PowerShell and the Skype for Business Online Connector. You may already have this installed from when you disabled this. If you need the instructions, you may find them here:
Once you have connected to your Skype for Business Online server, run the following command where ‘YourDomain.com’ is your own domain, e.g. via.co.uk
Enable-CsOnlineSipDomain -Domain YourDomain.com