Perfect. So the type of file that can be downloaded is pretty narrow for security reasons. The audio download option will accept mp3 and mpa file extensions. It’s not set up for video file downloading, but I believe we can add in that file type.
Go to the appearance section in your WordPress dashboard and click on Edit. From the list of files on your right, click on download.php. Delete everything there and replace it with this:
(see support site for code)
Save your changes. I believe that will add the mp4 file extension to the list of ones that can be downloaded. Let me know how that works for you.