JSFiddle - React, Tailwind, and code Playground

HTML

<iframe id="iframe" src="https://www.google.com"></iframe>
<button id="change-it">Go To</button>

CSS

#iframe {
    width: 100%;
}

JavaScript

var iframe = document.getElementById('iframe');
var button = document.getElementById('change-it');
button.addEventListener('click', function() {
	console.log(iframe.src);
    iframe.src = 'https://duckduckgo.com/';
    console.log(iframe.src);
});