How to use Browser Experiement when creating a web extension?

I want to know how I used the UrlBar Browser Experiment on Nightly builds for a personal extension that opens a new tab to a specific page but clears the address bar (url bar).

So I found this repo after doing some searching for how to replace the address bar text when opening a new tab. 0c0w3/dynamic-result-type-extension

So I am using a modified version of New Tab Override, but I cannot seem to get the classes that correspond to the api.js and schema.json to work.

Here is a link to my GitHub repo: thakyZ/firefox-newtab-homepage

If someone could help me figure out how to do this or figure out what I am doing wrong already, that would be very helpful!