David - one generic approach with all of the cloud based storage options is to write NPrinting output files locally to the appropriate 'synced' folder and simply let the desktop cloud app or native capabilities of the cloud sync keep the content replicated between the local NPrinting Server and the Cloud site. There are valid reasons to keep a copy of the report both on-prem and in the cloud. It's a simple approach that leverages the vendors own technology. To let NPrinting drop a file to a local folder is no different than a user dragging the file in.
For One Drive their documentation says:
To upload files to OneDrive automatically, just copy or move the files to your OneDrive folder using File Explorer, or save them in your OneDrive folder from a program. Files you upload this way can be up to 10 GB in size. If you installed the OneDrive app on other computers, the files will automatically be added to the OneDrive folders on them, too.