How to add a button to call a script in a Chrome extension?

Question

JavaScript

I packed the extension according to the instructions based on the archive (template), found a working example of adding a button to open a link to the extension's pop-up menu:

<a href="Ссылка на сайт" target="_blank">
 <button>
 <center>
 Название сайта
 </center>
 </button>

But I don’t know how to add a button to call a JS script, which I usually call from the browser console:

$('.class').each(function (counter, thing) {
    ...
    temp.click();
});