JSFiddle - React, Tailwind, and code Playground

HTML

<div id="button">Нажми меня</div>
<div id="button2">Нажми меня 2</div>
<div id="main"><iframe src="" width="100%" height="100%" ></iframe></div>

JavaScript

$('#button').on('click', function() {
    $('#main iframe')[0].src= 'https://youtu.be/1ygZZJWvmYQ';
});

var button2= document.getElementById('button2');
button2.onclick= function() {
    document.getElementById('main').getElementsByTagName('iframe')[0].src="/";
};