UI Help

[Engineer-of-Stuff]

I need some help with the UI. Whenever I enter the URL and click "Audio" or "Video", I get this message:

"Since we cannot run PHP code here, the download functionality is disabled for this demo version.

Note: You can find the source code of this demo in the gh-pages branch”

I downloaded both of the files (UI and the PHP thing) and put them in the same folder on my website file manager.