The commands to create a backup have nothing really to do with any particular OS, they're just HTTP urls. You could invoke them with a browser, if for nothing else than to test that you've got the syntax correct and a backup file is generated.
How you invoke the http command is, of course, specific to whatever OS or NAS or scheduler utility you have available. Does Unraid have a scheduler tool? If it's Linux based you might be able to use cron, but you're best bet might be to ask in the Unraid user forums.
