This is basic chrome extension using manifest v3 for configuration, you can embedded multiple js, or css file into the a website. You also can using background worker for process the js in the website.

• create new js file in src folder, and add to the function XXM.loadMore It look like

XXM.loadMore = function () {
    console.log("load more js")
    XXM.loadJS("src/your-code.js", () => console.log("done"), document.body)
}