JSFiddle - React, Tailwind, and code Playground

HTML

<h1 class="1" contenteditable="true">ELEMENT</h1>
<h1 class="2">ELEMENT</h1>
<h1 class="3">ELEMENT</h1>

JavaScript

$(".1").on('input',function() {
    $(".2").text($(this).text()); // set .text() instead .val()
    $(".3").text($(this).text());// set .text() instead .val()
});