Although duplicati-client seems the best-known way, it will need changes for new release, due to:
Battle plan for dropping HttpServer
It sounds from above that it might not be too hard, but the tool is third-party code we don’t control.
would also make sense for duplicati-client. Uglier case would be two versions to maintain forever.
A note on maintenance status by the duplicati-client author is worth noting for who does changes.