Why does Laravel passport authorize keeps loading? -

i created basic laravel passport authentication , created callback , redirect authorize user below code

route::get('/redirect', function () {     $query = http_build_query([         'client_id' => 4,         'redirect_uri' => 'http://localhost:8000/callback',         'response_type' => 'code',         'scope' => '',     ]);      return redirect('http://localhost:8000/oauth/authorize?'.$query); });  route::get('/callback', function (request $request) {     $http = new guzzlehttp\client;      $response = $http->post('http://localhost:8000/oauth/token', [         'form_params' => [             'grant_type' => 'authorization_code',             'client_id' => 4,             'client_secret' => 'muqufrtax3ix84zftxwqqxa5pqdy7swwvfw9tcnx',             'redirect_uri' => 'http://localhost:8000/callback',             'code' => $request->code,         ],     ]);      return json_decode((string) $response->getbody(), true); }); 

i followed steps provided on https://laravel.com/docs/5.4/passport when click on authorize button page keeps loading without response , have restart artisan serve. possible issue?