index copy.html

<!DOCTYPE html>
<html lang="en">
  <body>
    <div id="root"></div>
  </body>
  <script src="https://unpkg.com/react@18.2.0/umd/react.production.min.js"></script>
  <script src="https://unpkg.com/react-dom@18.2.0/umd/react-dom.production.min.js"></script>
  <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
  <script type="text/babel">
    const root = document.getElementById("root");
    let counter = 0;

    function countUp() {
      counter += 1;
    }

    const Container = () => (
      <div>
        <h3>Total Clicks : {counter}</h3>
        <button onClick={countUp}>Click me</button>
      </div>
    );

    ReactDOM.render(<Container />, root);
  </script>
</html>