Yes. Command Line Interface. Using Duplicati from the Command Line explains, if you’re curious.
That’s not going to work. It’s not a folder path. It’s the path to a backup’s DB file, ending in .sqlite
--dbpath
Path to the file containing the local cache of the remote file database.
and such text also describes the Local database path in the GUI Database page.
That’s because it’s not a per-backup option. It’s a server option affecting all backups.
Which path are you trying to take?
For per-backup DB, Database screen is simplest, and will move DB for you as said.
If you really prefer, you can instead add a per-job dbpath advanced option to override.
For all-backup setting including server DB, use server-datafolder/DUPLICATI_HOME.
It’s a bit of a pain to add server options and keep them around over uninstall/reinstall.
The exact method also depends on when and how you start Duplicati. Boot? Login?
Ultimately you usually wind up editing a shortcut right-click Properties to add options.
The question is which shortcut (depends on start method), and getting it to persist…
The DUPLICATI_HOME method makes this chore a little simpler. See earlier writeup.