Dropbox download to an absolute URL

The filesDownload method in the Dropbox API v2 JavaScript SDK is just a way to retrieve the file data from the Dropbox servers, and doesn't itself interact with your local filesystem. You can access the file data via the fileBinary property like you mentioned, and from there you can do whatever you need with the data, such as saving it to the local filesystem, etc.

For instance, here's an example that shows how you could save the downloaded file data from a download-style request (filesDownload works the same way) to the local file system using fs.