You can use the Commvault software to back up and restore Exchange Online.
Data You Can Back Up
Content: Emails, contacts, calendar, tasks, and conversations
Mailboxes: Primary mailbox, archive mailboxes, group mailboxes, shared mailboxes, public folder mailboxes, team mailboxes
Backups You Can Perform
When You Can Perform Backups
On a schedule: The server backup plan that you assign to the app manages scheduled backups
On demand: You can perform on-demand backups at any time
Backups You Can Use for Restores
Backups from any date/time, including the most recent backup
Destinations You Can Restore To
The current location (in place)
A different folder on the same client, or a different Exchange client (out of place)
A CAB, EML, or PST file
During backups and restores, both basic authentication and modern authentication can be used to access user data.