Backing up Roon database and library

I have an Innuous Zenith 3 (which I love). I make extensive use of Roon, with both Tidal and Qobuz subscriptions.  I have an external hard disc connected to the Zenith by usb, which I use for the Zenith’s backup function. But I really want to backup the Roon database and library. When I open Roon and go to backup, the only backup destination listed is Dropbox, which I do not subscribe to.  Roon doesn’t see any other backup options.  I know that others have used external hard drives and nas drives to backup their Roon database and library. I would really appreciate any help on how to do this. I have looked at the Roon instructions and tried to follow them with no success.  Another question: whenI do a backup on the Zenith, does that backup the Roon database and library or does it only backup cds which have been burned to the Zenith?  Thanks in advance for any help and happy new year!