https://www.4sitestudios.com/wp-content/plugins/en-iframe//js/iframe.js?ver=7.1.2

1function getFrameByEvent(event) {
2  return [].slice
3    .call(document.getElementsByTagName("iframe"))
4    .filter(function (iframe) {
5      return iframe.contentWindow === event.source;
6    })[0];
7}
8window.onmessage = (e) => {
9  var iframe = getFrameByEvent(e);
10  if (iframe) {
11    if (e.data.hasOwnProperty("frameHeight")) {
12      iframe.style.height = `${e.data.frameHeight}px`;
13    } else if (e.data.hasOwnProperty("scroll") && e.data.scroll > 0) {
14      // e.data.scroll will be the iframe offset to scroll, 1 = top of the iframe
15      const elDistanceToTop =
16        window.pageYOffset + iframe.getBoundingClientRect().top;
17      let scrollTo = elDistanceToTop + e.data.scroll;
18
19      window.scrollTo({
20        top: scrollTo,
21        left: 0,
22        behavior: "smooth",
23      });
24      console.log("Scrolling Window To", scrollTo);
25    }
26  }
27};