How to make an external script load lazy in Wordpress?

Question

JavaScript

Online chat scripts for a site from Bitrix24 or from Vkontakte are loaded with a long TTFB.
I've tried everything, I can't set it up so that they are loaded after the site page is fully loaded. For LPTracker, this works fine, but on the developer's side.

Answer 1

This is what worked for me

<script>
var scripts = new Array('путь/до/файла.js');
  var css = new Array('путь/до/styles.css');

  function downloadJSAtOnload() {
    var element;
    for(var i = 0; i < scripts.length; i++){
      element = document.createElement("script");
      element.src = scripts[i];
      element.type = 'text/javascript';
      document.body.appendChild(element);
    }
    for(var i = 0; i < css.length; i++){
      element = document.createElement("link");
      element.href = css[i];
      element.type = 'text/css';
      element.rel = 'stylesheet';
      document.body.appendChild(element);
    }
  }
  if (window.addEventListener)
    window.addEventListener("load", downloadJSAtOnload, false);
  else if (window.attachEvent)
    window.attachEvent("onload", downloadJSAtOnload);
  else window.onload = downloadJSAtOnload; 
</script>

Answer 2

wp_enqueue_script('newscript', '//js/custom_script.js', array(), '1.0.0', true);

Isn't it the same? Include the script before the closing body.

Answer 3

After the page loads, create a script tag and load it.