When activating individual user backups, the Admin account must have Impersonation and be a member of the Management Group.
Follow the next steps to configure impersonation:
1. On your Office 365 dashboard click on the “Admin” menu.
2. Click on the “Exchange” menu item.
3. Click on “permissions” and double click on “Discovery Management…”.
4. Add the “ApplicationImpersonation” Role to this roles group and click on “Save”.
5. Click on “permissions” and double click on ”Organization Management …”
6. Add the “ApplicationImpersonation” Role to this roles group.