It is possible to back up Teams channel posts, private chats messages or both. You can find the relevant toggles on Backup portal's Settings page.
Note
For your customers whose backups were enabled prior to the launch of Teams chat backup, you need to grant the Teams chat related permissions for the backup application in Microsoft Entra admin center. See the instruction here. Additional permissions are needed to back up both channel posts and private chats.
Enable backup for Teams channels
1. Click the Settings icon in the top-right corner.
2. On Settings page, select Organisation services.
3. Click the Teams channel posts slide switch to enable backup for Teams channels. Both Public and Private Teams channels are included in backup.
4. Click Save.
Enable backup for Teams private chats
1. On Settings page, select User services.
2. Choose All users or Users in AD Groups, depending on your backup configuration choices.
3. Click the Teams private chats slide switch to enable backup for private chats in Teams.
4. Click Save.