Embed iframe dynamically using script

My questions is almost exactly like the one here: https://www.wix.com/corvid/forum/community-discussion/dynamic-page-with-html-embedded-with-url-from-database?origin=auto_suggest

Currently I’m using the postMessage thing with corvid and code:

import wixData from 'wix-data';

$w.onReady(function () {

  wixData.query('Items') 
  .find()
  .then(res => {    
    let DataRow = res.items;  
    let strURL = res.items[0].url; // Getting first url for simplicity
    $w("#html1").postMessage(strURL);
  });

});

HTML Element:

  <html>
  
  <head>
    <script type="text/javascript">
      window.onmessage = (event) => {
        if (event.data) {
          	document.getElementById("jack").src = event.data;
        }
      };
    </script>
  </head>
  <body>
    <script id="jack" type="text/javascript"></script>
  </body>
</html>

A quick look at inspect element shows that its properly setting the src of the script, but nothing else is happening. I’ve tried every variant of this and sometimes I get the error X-FRAME option set to sameorigion… and sometimes ‘Failed to execute ‘write’ on ‘Document’: It isn’t possible to write into a document from an asynchronously-loaded external script unless it is explicitly opened.’…

Has anyone successfully loaded an iframe from an external domain dynamically via postMessage?