You can add a Cosmos DB SQL API instance using an existing Azure account.
From the navigation pane, go to Protect > Databases.
The Instances page appears.
Click Add Instance, and then click Cloud DB.
The Add Cloud DB instance page appears.
From the Select vendor list, select Microsoft Azure.
From the Database service list, select Cosmos DB.
From the API list, select SQL API.
In the Instance box, enter a name for the instance.
From the Cloud account list, select the Azure account that you want to use for the instance.
If the cloud account that you selected uses an access node that includes only the Virtual Serverpackage, then in the Access node list, select an access node that has both the Virtual Server and Cloud Apps packages installed.
From the Plan list, select the server plan to use for the instance.
To filter the content that is backed up, for Backup content, click Edit, and then select or clear the databases or containers.
What to Do Next
A container group is created for the instance. You can create more container groups to meet different backup requirements.