W3Schools Tryit Editor

main.jsx

index.html

import { createRoot } from 'react-dom/client';
import { BrowserRouter, Routes, Route, Link, useParams } from 'react-router-dom';

function Info() {
  const { firstname } = useParams();
  return <h1>Hello, {firstname}!</h1>;
}

function App() {
  return (
    <BrowserRouter>
      <nav>
        <Link to="/customer/Emil">Emil</Link> | 
        <Link to="/customer/Tobias">Tobias</Link> |
        <Link to="/customer/Linus">Linus</Link>
      </nav>

      <Routes>
        <Route path="/customer/:firstname" element={<Info />} />
      </Routes>
    </BrowserRouter>
  );
}

createRoot(document.getElementById('root')).render(
  <App />
);

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