you would need to store the uploaded file name into a database to retrieve the file name on the download page.
on the download page, you can either use a link or the File Manipulation -> Download file behavior, and retrieve the file name from the database using a recordset.
On the Digital File Pro support page, see the tutorial for "How to apply Digital File Pro to DataAssist Insert and Update pages" this will walk through storing the file name, and showing the file on the results page if it is an image, the concept is similar for other files, except you use a link instead of an image tag:
digital-file-pro/