JSFiddle - React, Tailwind, and code Playground

HTML

<div id='iframeNormal' class='iframes'> some text 1 </div>
<div id='iframePortal' class='iframes'> another 1 </div>

CSS

.iframes
{
    display: none;
}

JavaScript

var div1 = document.getElementById('iframeNormal');
var div2 = document.getElementById('iframePortal');

if (window.location.host.indexOf('w3schools') !== -1)
{
div1.style.display = 'block';
}
else
{
div2.style.display = 'block';
}