If you can't disable mutli-factor authentication for the Office 365 global administrator account, which is required by the express configuration option, use the custom configuration option. Use this option if the same person performs the roles of backup administrator, Office 365 administrator, and Azure administrator.
Before using the custom configuration, you must register the Azure app for Teams with Azure AD.
Before You Begin
Verify that you have a user account that is licensed for Teams.
The user account is added to all the Teams channels as a member so that the backup process can access the data of each team. If notifications are turned on for users, users are notified that an account was added to the channel as a member.
If you do not want an authorized user account to be added as a member of the team, follow the instructions in KB article 67692.
Important: You can perform the registration manually, as described in step 1, or you can use the custom configuration toolkit. The toolkit, which automates the registration process, is available in step 2.