After you have added the @voice domain names in the Microsoft Admin panel, you need to activate them by adding at least one E1, E3, or E5 licensed user to the newly created base domain.
You can do this by either creating a new temporary user or using an existing user. You need to keep the domain names attached to the user for at least 60 minutes for the activation to be completed. This is a process required by Microsoft and mandatory before proceeding.
Creating and assigning an 'alias' for an existing user will not activate the domain name
Create a new user:
On the Microsoft Admin Panel:
On the left menu from the Microsoft admin page, select Users - Active Users. Click on Add a user. Enter a First name, Last name, Display name and Username. Then select the @voice domain name that you are activating (you will need to activate both domain names). Set a Password and click on Next.
Next, in the dropdown list for Select location, select Australia and under Assign user a product license, assign either an E1, E3 or E5 license for this user and click Next.
Under Optional settings, you don't need to change anything here (as this is just a temporary user and you will be deleting the user after the activation process is completed). So you can just go ahead and click Next and Finish adding.
Now comes the waiting part. You will need to wait for at least 60 minutes before either deleting the new user you created or switching the existing user back to the original domain.
You will need to do this for both @voice domains provided.