Getting error invalid json token in laravel package

Currently implement a google drive API.Getting error invalid json token in laravel package.

Tutorial : https://www.sitepoint.com/is-laravel-good-enough-to-power-a-custom-google-drive-ui/

<?php
namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Googl;

class HomeController extends Controller
{
    public function index()
    {

        return view('login');
    }


    public function login(Googl $googl, Request $request)
    {
        $client = $googl->client();

        if ($request->has('code')) {            
            $client->authenticate($request->input('code'));
            $token = $client->getAccessToken();

            $plus = new \Google_Service_Plus($client);

            $google_user = $plus->people->get('me');
            $id = $google_user['id'];

            $email = $google_user['emails'][0]['value'];
            $first_name = $google_user['name']['givenName'];
            $last_name = $google_user['name']['familyName'];

            session([
                'user' => [
                    'email' => $email,
                    'first_name' => $first_name,
                    'last_name' => $last_name,
                    'token' => $token
                ]
            ]);


            return redirect('/dashboard')->with('message', ['type' => 'success', 'text' => 'You are now logged in.']);

        } else {
            $auth_url = $client->createAuthUrl();
            return redirect($auth_url);
        }
   }
}

via Chebli Mohamed