firebase.js

import { initializeApp, getApp } from "firebase/app";
import { initializeAuth, getAuth, getReactNativePersistence } from "firebase/auth";
import { getFirestore } from "firebase/firestore";
import Constants from "expo-constants";
import ReactNativeAsyncStorage from "@react-native-async-storage/async-storage";

// Firebase config
const firebaseConfig = {
  apiKey: Constants.expoConfig.extra.apiKey,
  authDomain: Constants.expoConfig.extra.authDomain,
  projectId: Constants.expoConfig.extra.projectId,
  storageBucket: Constants.expoConfig.extra.storageBucket,
  messagingSenderId: Constants.expoConfig.extra.messagingSenderId,
  appId: Constants.expoConfig.extra.appId,
  databaseURL: Constants.expoConfig.extra.databaseURL
  //   @deprecated is deprecated Constants.manifest
};

// initialize Firebase App
const app = initializeApp(firebaseConfig);
// initialize Firebase Auth for that app immediately
export const auth = initializeAuth(app, {
  persistence: getReactNativePersistence(ReactNativeAsyncStorage)
});

// initialize firebase
initializeApp(firebaseConfig);
export const database = getFirestore();