How to use React Router with Laravel?

Route::get('{reactRoutes}', function () {
    return view('welcome'); // your start view
})->where('reactRoutes', '^((?!api).)*$'); // except 'api' word

Route::get('api/whatever/1', function() {
    return [
        'one' => 'two',
        'first' => 'second'
    ];
});

Route::get('api/something/2', function() {
    return [
        'hello' => 'good bye',
        'dog' => 'cat'
    ];
});

import React from 'react';
import {
    HashRouter,
    Route,
    Link
}from 'react-router-dom';
import Profile from './Profile';

export default class App extends React.Component {
    constructor(props) {
        super(props);
    }

    render() {
        return (
            <HashRouter>
                <Link to="/profile" replace>Profile</Link>
                <Route path="/profile" component={Profile}/>
            </HashRouter>
        );
    }
}

Route::get('/', function(){
    return view('index'); //This view is supposed to have the react app above
});

Route::pattern('path', '[a-zA-Z0-9-/]+');
Route::any( '{path}', function( $page ){   
     return view('index');
});