// Outputting div
<div class="postButtons pw-server-widget" data-id="wid-oq19btvv"></div>

// Post's JS is included with PHP, but here's the jist of it:
$js = <<<JS
    (function () {
      var s = document.createElement("script");
      s.type = "text/javascript";
      s.async = true;
      s.src = ('https:' == document.location.protocol ? 'https://s' : 'http://i')
        + '.po.st/static/v4/post-widget.js#publisherKey=$pub_key';
      var x = document.getElementsByTagName("script")[0];
      x.parentNode.insertBefore(s,x);
    })();
JS;

// This is just me testing out some of the JS methods, is this on the right track?
// The setTimeout is just for testing.
setTimeout(function () {
  window.postPlatform.init('.pw-server-widget');
    console.log(window.postPlatform, 'window.postPlatform');
}, 2000);