const App = () => {
  const handler = (e) => {
    e.preventDefault();
    window.alert(`你按下了${e.key} 按鍵，按鈕是 ${e.keyCode}`);
  }

  return (
    <div>
       <input type="text" onKeyDown={ handler } />
    </div>
  )
}

const app = document.querySelector('#app');
const root = ReactDOM.createRoot(app);
root.render(<App />);