JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
  <li>1</li>
  <li>12</li>
  <li>356</li>
  <li>dfhg</li>
  <li>fghsfg</li>
</ul>
<ul>
  <li>1</li>
  <li>12</li>
  <li>356</li>
  <li>dfhg</li>
  <li>fghsfg</li>
</ul>

JavaScript

document.querySelectorAll('li').forEach(el => el.setAttribute('contenteditable', true))