In Windows 10 you could:
- set up the backup using the Duplicati Web GUI
- export the backup job “As Command-line” and copy the results
- do a Windows / Cortana search for and run “Task Scheduler” (not Task Manager)
- in the Actions menu on the right click on “Create basic task”
- give it a name (such as “Duplicati XXX backup”) where XXX is the name of your job and click the Next button
- select how you want the task to be triggered (such as Daily) and click the Next button
- fill in the details for the trigger type (if applicable) and click the Next button
- select and Action of “Start a program” and click the Next button
- in “Program/script” paste
"C:\Program Files\Duplicati 2\Duplicati.CommandLine.exe"
(or whatever your Command-line begins with)
a. in “Add arguments (optional)” paste the REST of your Command-line (everything after CommandLine.exe)
b. click the Next button - click the Finish button
There are other ways to do this, of course - but hopefully that will be enough to get you started!