JSFiddle - React, Tailwind, and code Playground

HTML

<ol class="spisok">
       <li>Text</li>
       <li>Text</li>
       <li>Text</li>
 </ol>
<button class="button">click me</button>

JavaScript

document.querySelector('.button').addEventListener('click', () =>{
let i = document.querySelector('.spisok').children.length + 1
const node = document.createElement("LI");
const textnode = document.createTextNode(i);
node.appendChild(textnode);
document.querySelector('.spisok').appendChild(node);
})