Force file download once a site is visited

I have a simple site example.com and an external file link. I want this scenario to be implemented: Once a user visits example.com, a file from an external link is automatically downloaded. Mind that I don't want a user to click some link, but just an immediate file download once the site is visited. Thus <a href="link/to/file" download>Download</a> is not what I need. Thanks in advance.