How to code HTML download button where filename version will change Options

[larry78723]

I'm creating a webpage where the user will be able to download an .iso file. The version of the iso will change. For example: xxxx.1.iso will become xxxx.2.iso when the iso is updated. How do I code the download button so that I don't need to re-code the button when the version changes. If I were to create a download subdirectory, and the .iso file was kept there do you think this would work if the only file in the download subdirectory is the .iso file?

<?php
$files = array_slice(scandir('/download/'), 2);
?>
<div class="navbar-custom">
<a class="btn-solid-lg page-scroll" href="/Download/" download=$files>Download the App</a>
</div>