Запуск reactjs на хостинге

Делаю yarn build yarn global add serve serve -s build

import React, { Component } from 'react';
import './App.css';
import { Link } from 'react-router-dom';
import  firebase from 'firebase';
import {DB_CONFIG} from './Config.js'
import Collapsible from 'react-collapsible';
class App extends Component {
 constructor(){

    const login = window.localStorage.getItem('rr_login')
    if (login == '330') {
      console.log('пропусти')

      super()
      this.state = {
        currentItem: '',
        username: '',
        items: []
      }
      this.app = firebase.initializeApp(DB_CONFIG);
      const dateTime = new Date().getTime();
      const timestamp = Math.floor(dateTime / 1000);
      var key = parseInt(timestamp/86400);
      this.database = this.app.database().ref('driversApp/ordersData/').child(key);
    }
  }
  /* ... */
}
export default App;