如何在react firebase-ui中发现用户是否是第一次登录？

import React, { useEffect } from 'react';
import firebase from 'firebase/app';
import 'firebase/auth';
import { FirebaseUIAuth } from 'firebaseui-react';

const firebaseConfig = {
  // Your Firebase config here
};

if (!firebase.apps.length) {
  firebase.initializeApp(firebaseConfig);
}

const App = () => {
  const checkFirstLogin = async (user) => {
    if (user) {
      const userDoc = await firebase.firestore().collection('users').doc(user.uid).get();
      if (!userDoc.exists()) {
        console.log('First time login');
        // Perform actions for first time login, e.g., redirect to onboarding page
      } else {
        console.log('Not the first time login');
      }
    }
  };

  useEffect(() => {
    const unsubscribe = firebase.auth().onAuthStateChanged(checkFirstLogin);
    return () => unsubscribe();
  }, []);

  return (
    <div>
      <FirebaseUIAuth
        uiConfig={{
          signInSuccessUrl: '/home',
          signInOptions: [
            firebase.auth.EmailAuthProvider.PROVIDER_ID,
            firebase.auth.GoogleAuthProvider.PROVIDER_ID,
          ],
        }}
      />
    </div>
  );
};

export default App;