npm install --save react react-dom
npm install react-router@3.0.5 --save

image.png

import React from'react';
import ReactDOM from 'react-dom';
import'./index.css';
import App from './App';
import registerServiceWorker from './registerServiceWorker';

import { BrowserRouter,HashRouter,Route }from 'react-router-dom';

function home(){
return <h2>Home Page</h2>
}
ReactDOM.render(
<HashRouter>
    <Route path='/' component={home}></Route>
</HashRouter>,document.getElementById('root')
);

registerServiceWorker();