Backups are only available with the paid Backups option (price shown on the service page), added from the service page's Add-ons tab (billed pro rata). With the option, the GamePanel's Backups menu (Management group) creates and restores backups; backup storage equals 50% of your storage and scales with your upgrades. Without the option, download the world folder through the File Manager or via SFTP.
With the Backups option: GamePanelManagementBackupsCreate, before any update or mod install.
To roll back: choose the backup, then Restore. Current files are replaced.
To add the option: client area, service page, Add-ons tab, Backups, Add.
Service page's Add-ons tab: the Backups option and its Add button