script to transfer files from remote server directly to Dropbox

The Dropbox API itself doesn't offer a way to get files directly from SSH connections like this, but to clarify, note that the "path" parameter you're referring to is how you specify where in the connected Dropbox account you want to put the uploaded file. It is not how you specify where the actual file data to upload comes from.

You send the file data you want to upload to the Dropbox API /2/files/upload endpoint in the HTTPS request body. In this curl example, that's done via curl's '--data-binary' option. In this sample, you're telling curl to upload the data from the local file with the name "local_file.txt" from the current directory.

You might be able to connect scp or ssh to curl and pipe the data directly through to the Dropbox API endpoint, though I don't have a sample of how that might work. You'd need to refer to the ssh, scp, and/or curl documentation for more information.