Jottacloud comes with a sync tool which I downloaded for my Mac. There is an app for Mac 10.15 or later and Windows. No Linux app yet.
The tool is very simple to use, you select the folders you want to back up and select upload and the selected files or folders are synced to the Jotta cloud.
Syncing can be automated, so whenever you make a change to a file or folder, the change is synced to the Jotta cloud.
I find the system easy to use. I have a fairly fast internet connection so it was not too long to do the initial back up.
So far I can recommend Jottacloud for photos, docs and backups and the product has made my move away from Google so much easier!
Pro Tip: Get better pricing on space through the Mobile App!