installation

refer to https://docs.expo.dev/guides/using-firebase/ the tutorial uses firebase@9.1.0

expo install

in your terminal, install firebase@9.1.0

expo install firebase@9.1.0

Config/firebase.js

import { initializeApp } from 'firebase/app';
import { getFirestore } from "firebase/firestore";

const firebaseConfig = {
  apiKey: "xxxxx",
  authDomain: "xxxxx",
  databaseURL: "xxxxx",
  projectId: "xxxxx",
  storageBucket: "xxxxx",
  messagingSenderId: "xxxxx",
  appId: "xxxxx",
  measurementId: "xxxxx"
};

// Initialize Firebase
const app = initializeApp(firebaseConfig);
export const db = getFirestore(app);

Calling your firestore DB

In this example, we are calling user datas

import React, { useEffect } from 'react'
import { db } from '../Config/Firebase'

function FeedScreen() {
const [data,setData]=useState()
	const feedData=async()=>{
		try {
			const querySnapshot = await getDocs(collection(db, "users"));
			querySnapshot.forEach((doc) => {
			console.log(`${doc.id} => ${doc.data()}`);
			});
		} catch (error) {
			console.log(error.message,'error here')
		}
		
	}
useEffect(() => {
feedData()
  return () => {	
  }
}, [])

return(

)
	
	
}