lucide/docs/guide/react/advanced/examples/combining-icons-notification/App.js

import { Mail } from "lucide-react";

function App() {
  const hasUnreadMessages = true;

  return (
    <div className="app">
      <Mail size={48}>
        {hasUnreadMessages && (
          <circle
            r="3"
            cx="21"
            cy="5"
            stroke="none"
            fill="#F56565"
          />
        )}
      </Mail>
    </div>
  );
}

export default App;