POST to new tab from Popup Script - Chrome Extension

I am trying to open a new tab on chrome and make a POST request to it, as soon as it opens. I have found this answer, which, as far as I understand, 'is creating a form element with a content script and posting the form'. However, I am not sure if this is the best way to go for doing it from a popup script.

(Simplifying everything down), I have my popup.html like this:

<button>Post</button>
<script src="../popup.js"></script>

And popup.js,

$('button').click(function() {
    // open a new tab and do a POST request
});

At this point, should I create a background script and do what Xan did here? Or did I have some misunderstanding what background can/cannot do? I am pretty confused on how to implement the "open a new tab and do form POST request" approach on a popup script.