JSFiddle - React, Tailwind, and code Playground

HTML

<a id="my" href="/web/luas">MyLink</a>

<div id="log">
</div>

JavaScript

var d = document.getElementById( 'my' ),
    log = document.getElementById( 'log' );
    
log.innerHTML += d.hostname + '<br/>';

d.setAttribute('href',"/my/other/link");
log.innerHTML += d.hostname;