JSFiddle - React, Tailwind, and code Playground

HTML

<div id="el1"></div>
<button id="btn1">change subtext2</button>

JavaScript

var el1 = document.getElementById('el1');
var targetTextNode = document.createTextNode('subtext2');


el1.appendChild(document.createTextNode('subtext1'));
el1.appendChild(targetTextNode);
el1.appendChild(document.createTextNode('subtext3'));

document.getElementById('btn1').onclick = function() {
    targetTextNode.nodeValue = ' ЖОПА! ';
};