In order to send documents via Dropbox without appearing the preview so that the user has access to a direct download link, we only need to make a little change on the document link.
Original Dropbox link:
Link:
https://www.dropbox.com/s/9s03c458wfg6yn8/ejemplo.pdf?dl=0
We only have to change the last URL digit:
in the “0” we place “1” instead.
The direct download link would then remain like this: