Overview:
Refer to this knowledge base article for adding licenses to an existing Microsoft 365 Business subscription in Xvantage.
Process:
Log in to Xvantage.
Hover over the left navigation menu and click My Business.
Then, select Subscriptions.
Locate the subscription that needs action by using the search bar or the filter function.
Once located, click on the Subscription ID under the Subscriptions column.
In the upper-right corner of the subscription page, click the Change dropdown, then select Plan or quantity.
You can either increase the quantity of licenses you need or select a higher subscription plan to upgrade the license.
Click Next and follow the prompts until the system gives you an order number that starts with CH.