An example of how to load a script on scroll in Shopify

load-on-scroll.txt

<script type="text/javascript">  
  window.addEventListener('scroll', scrollyScroll, false); 

  function scrollyScroll() {
    let scrollPosition = 0;
    scrollPosition = window.scrollY;
    if (scrollPosition > 10) {
      (function() {
        var tidScript = document.createElement('script');
        tidScript.type = 'text/javascript';
        tidScript.async = true;
        tidScript.src = 'https://scriptGoesHere';
        (document.getElementsByTagName('body')[0]).appendChild(tidScript);
      })();
      stopIt();
    }};

  function stopIt (){
    window.removeEventListener('scroll', scrollyScroll)
  }
</script>

previous iterations didn't properly apply the listener event. had to update to remove, otherwise was firing over and over again. won't impact performance on speed tests, but likely could have caused user errors from firing repetitively.