is it possible to launch an extension from javascript?

for example in my code i check if a specific keyword is in the url with:

let keyword = "xyz"

if (window.location.href.indexOf("keyword") > -1) {
            window.location.replace("https://www.google.com/");
        }

and if it is in the url, i get redirect to google.com

the problem is that if i try to open my index.html, it opens it as a website instead of an extension popup

so how can you open it as an extension, if you can?

thanks