Instead installing makes me download a file

I’m using virtualmin to install prestashop. I already installed PHP 7.2 (because it gave me an error from the missing php version) and uploaded the zip installation into the public html and extracted it then it makes me download the php file.
Don’t know what to do with this king of behavior.

Thanks in advance
error

Operating system: Linux
OS version: Debian 10

Hi,

You need to go to Server Configuration > Website Options page and set/change PHP execution mode: