W3Schools Tryit Editor

main.jsx

index.html

import { createRoot } from 'react-dom/client'

function kwtohp(kw) {
  return kw * 1.36;
}

function Car() {
  return (
    <>
      <h1>My car</h1>
      <p>It has {kwtohp(218)} horsepower</p>
    </>
  );
}

createRoot(document.getElementById('root')).render(
  <Car />
);

<!doctype html>
<html lang="en">
  <body>
    <div id="root"></div>
    <script type="module" src="/src/main.jsx"></script>
  </body>
</html>