// Simple Google Sign-in/out Setup [Firebase v9]

import { useAuthState } from 'react-firebase-hooks/auth';

import { initializeApp } from "firebase/app";

import { getAuth, signInWithPopup, GoogleAuthProvider, signOut } from "firebase/auth";

const firebaseConfig = {

  apiKey: "<...>",

  authDomain: "<...>",

  projectId: "<...>",

  storageBucket: "<...>",

  messagingSenderId: "<...>",

  appId: "<...>"

};

const firebaseApp = initializeApp(firebaseConfig);

const auth        = getAuth(firebaseApp)

const provider    = new GoogleAuthProvider();

​

const googleSignIn  = async () => await signInWithPopup(auth, provider); 

const googleSignOut = () => signOut(auth); 

​

export default function App(){

  const [user] = useAuthState(auth); 

  return user ? <button onClick={googleSignOut}>Logout</button> : <button onClick={googleSignIn}>Sign in with Google</button>

};