Read and Write using firebase(realtime database) in React JS

npm i firebase

import "firebase/auth";import "firebase/database";import { initializeApp } from 'firebase/app';import { getDatabase } from "firebase/database";const firebaseConfig = {  apiKey: "YOUR_API_KEY",  authDomain: "YOUT_AUTH_DOMAIN",  databaseURL: "YOUR_DATABASE_URL",  projectId: "YOUR_PROJECT_ID",  storageBucket: "YOUR_STORAGE_BUCKET",  messagingSenderId: "YOUR_MESSENGER_SENDER_ID",  appId: "YOUR_APP_ID"};// Initialize Firebaseexport const app = initializeApp(firebaseConfig);export const database = getDatabase(app);

function writeData() {    const db = getDatabase();    const postListRef = ref(db, 'users/'); //    const newPostRef = push(postListRef);    set(newPostRef, {      username: item,    });  }

const Deletedata = (e) => {    const db = getDatabase();    remove(ref(db, `users/${e.key}`));  }

const Ref = ref(database, 'users/',);  useEffect(() => {    onValue(Ref, (snapshot) => {      const data = snapshot.val();    });  }, [])