On the Atomic portal:
When you create an Account, please ensure that you you select a Microsoft Team Service Plan. If you do not see a Microsoft Teams Service Plan, please check with your Account Manager to get that activated for you.
You will also need to select the relevant Customer that this service will be attached to.
When creating an Account with a Microsoft Teams Service Plan, select the number of channels that is required. You can always come back to the Account and add additional channels as required.
Enter the other relevant account settings that you need and click on Create Account.
When you setup an account with a Microsoft Teams Service Plan, you will be assigned a unique Teams Domain name. To view the domain name, click on the 'Connection' icon next to the Account in Account List. The domain name is how the Atomic platform authenticates and handles the calls between accounts with Microsoft Teams.
For now, just copy down the domain name as the domain name will need to be added to the users Microsoft Office 365 tenant account.