W3Schools Tryit Editor

main.jsx

index.html

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

function MyForm() {
  const [name, setName] = useState("");

  function handleChange(e) {
    setName(e.target.value);
  }

  function handleSubmit(e) {
    e.preventDefault();
    alert(name);
  }

  return (
    <form onSubmit={handleSubmit}>
      <label>Enter your name:
        <input
          type="text" 
          value={name}
          onChange={handleChange}
        />
      </label>
      <input type="submit" />
    </form>
  )
}
createRoot(document.getElementById('root')).render(
  <MyForm />
);

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