JSFiddle - React, Tailwind, and code Playground

HTML

<div class='myclass'>
  <ul>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
    <li><span></span></li>
  </ul>
</div>

CSS

ul {
  margin: 0;
  padding: 0;
}
li {
  list-style-type: none;
}

JavaScript

let spans = document.querySelectorAll("span");
for (let i = 0; i < spans.length; i++) {
	if (i < 10)
		spans[i].innerHTML = '0' + i.toString();
	else
		spans[i].innerHTML = String(i);
}