hanabi | an ok implementation of the best game | Game Engine library

i'm developing a quiz website. In my database, I need a table which shows reported quiz errors. It should look like this:

I'm trying to use XmlHttpRequest to run a php script from a javascript file. But for some reason, my code is only returning the php code as a string instead of actually running it.

The php runs perfectly fine if I run it alone from a global url, but it won't run from the javascript file, implying there's something wrong with my javascript request?

I'm running everything locally on Ubuntu with Apache and nodejs. I was directed to this link earlier: PHP code is not being executed, instead code shows on the page, but it seems Ubuntu does not have an httpd.conf file and uses an apache2.conf instead. I'm not sure what the difference is or how to mess with it without breaking it. Also, doesn't the above link only imply that it's php's fault? But my php file runs perfectly fine when accessed through a global url.

Here's the snippet of javascript that's supposed to call the php file: