dave1 Instead of a button, add a MC-Single answer question with one or two options; with one of the options being 'Download the dataset' (the second option if you want to include could be to skip the download step). In the survey flow, adda branch after that block; the condition is if 'Download dataset' is selected. The add an 'End of Survey' element and customize it for a Redirect to URL. Add your private URL and the users will be rerouted to that if they choose the Download option.

https://community.qualtrics.com/XMcommunity/discussion/comment/39626#Comment_39626Hi, much thanks for your feedback and suggestion.
We have tried this before and it all works well until the Redirect ("Please wait while you are redirected").
However, our private download URL becomes visible once the user moves the mouse cursor on the sentence "Click here if you are not automatically redirected" (see screenshot below).

I tried to redirect to a pdf link and did not get that screen. Check out this survey link. I do not know if the specific type of link in your case is forcing that page.

You can set up a button to to download the file, however, the user will still have access to the url in their downloads page.
The only way to completely hide is at the server side.