Fix the plain variable — find the bug

function App() {
  let count = 0
  return (
    <div>
      <p id="value">{count}</p>
      <button id="inc" onClick={() => { count = count + 1 }}>add</button>
    </div>
  )
}
const root = ReactDOM.createRoot(document.getElementById("root"))
root.render(<App />)