JSFiddle - React, Tailwind, and code Playground

HTML

<body>
<div class="div1">
stuff
</div>
<div class="div2">
<a href="https://jsfiddle.net/user/login/">link</a>
</div>
</body>

JavaScript

var replaceThis=document.querySelector('.div1');
var withThis=document.querySelector('.div2 a').getAttribute("href");
//console.log(withThis);
replaceThis.innerHTML='<object type="text/html" data="'+withThis+'" style="width: -webkit-fill-available;height: -webkit-fill-available;"></object>';
var thingFromEmbeddedSite=document.querySelector('.div2');//returns div2
console.log(thingFromEmbeddedSite);
thingFromEmbeddedSite=document.querySelector('h2');//returns null
console.log(thingFromEmbeddedSite);