Chrome Extension: Loading an analytics file in the popup file

I’m building a Chrome Extension that features both a popup and a content file. I’m trying to load a SiteCatalyst s_code.js file in to the popup for anayltics purposes.

Loading the file via the standard tag in the index.html file doesn’t work. I’ve tried using the example here: how to load JS from a chrome extension popup – that uses the chrome.runtime.getBackgroundPage(function callback) example like so:

In my index.html file:

In my popup.js file:

chrome.runtime.getBackgroundPage(trackingPage => trackingPage.testMethod());

And in my tracking/s_code.js file:

const testMethod = () => console.log('s_code loaded');

I’ve also added the reference to the file in my manifest.json under web_accessible_resources and content_scripts (this file will be needed in both popup and content areas.