Is there a way to use a remote folder as a source? I seem to be able to use ssh for destination but not as source data.
Duplicati is great by the way. Thanks for all who is involved.
It’s not possible from within Duplicati. You could mount a remote folder into your file system without Duplicati knowing, but you will get terrible performance 
in general, I’d recommend backing up only local data.
If you need to back up data on a system that cannot run Duplicati I’d sync the data down with rsync or some other utility and then back up the local copy in Duplicati.