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>

the console.log(scrollPosition) was really just used to make certain that the event listener got removed window.onscroll == null and is not necessary.

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.