const App =() => {
  const [userText, setUserText] = useState("");

  useEffect(() => {
    const handleUserKeyPress = event => {
      const { key, keyCode } = event;

      if (keyCode === 32 || (keyCode >= 65 && keyCode <= 90)) {
        setUserText(`${userText}${key}`);
      }
    };

    window.addEventListener("keydown", handleUserKeyPress);

    return () => {
      window.removeEventListener("keydown", handleUserKeyPress);
    };
  }, [userText]); // ESLint will yell here, if `userText` is missing

  return (
    

      
Feel free to type!
      
{userText}
    
  );
}

ReactDOM.render(, document.getElementById("root"));