Lazy Load GTM

gistfile1.txt

<script>
function loadScript(url) {
    let isLoaded = document.querySelectorAll('.search-script');
    if(isLoaded.length > 0) { return; }
    let myScript = document.createElement("script");
    myScript.src = url;
    myScript.async = 'async';
    myScript.className = 'search-script';
    document.head.appendChild(myScript);
}
  
window.addEventListener('scroll', function() {
    var timer;
    clearTimeout(timer);
    timer = setTimeout(function() { loadScript('https://www.googletagmanager.com/gtm.js?id=YOUR-ID'); }, 1000);
});
</script>