JSFiddle - React, Tailwind, and code Playground

HTML

<form id="frmName">
    <input type="text">
    <textarea id="textBox">ololo trololo</textarea>
</form>
<input type="button" value="piu" onclick="toggle('textBox')">

JavaScript

function _e(id) {
    return document.getElementById(id);
}

function toggle(id) {
    _e(id).disabled = !_e(id).disabled;
}