IFrame get scroll position

Question

I am scrolling a pdf file inside an Iframe and trying to access the scroll position but failed to do so. tried all the resources but they don't seem to work anymore. Any help is Greatly Appreciated.

const iframe = document.getElementById('iframe');

iframe.onload = function() {
  console.log("IFrame Loaded")
  const iframeDoc = iframe.contentDocument || iframe.contentWindow.document;
  iframeDoc.addEventListener('scroll', function() {
  console.log("Scrolling Started")
  console.log(iframeDoc.documentElement.scrollTop);
});
};