JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<body>
  <p id="p" contenteditable="true"><i>italic</i><b></b></p>

  <button id="button">Click to focus</button>
  <script>
    button.onclick = () => {
      let range = new Range();

      range.setStart(p.childNodes[1], 0);
      range.setEnd(p.childNodes[1], 0);

      window.getSelection().removeAllRanges();
      window.getSelection().addRange(range);
    };
  </script>
</body>