'Not Logged In' error facebook api

i get the following error from FaceBook api:

‘Not Logged In: You are not logged in. Please login and try again.’

I’m using laravel 5, and php-sdk-v4 library so i add the callback page as fucnction in a controller, .

namespace AppHttpControllers;

use IlluminateHttpRequest;
use AppHttpRequests;
use Session;
use Facebook;

class FacebookLoginController extends MainController {

    public function login() {

        $fb = new FacebookFacebook([
            'app_id' => '****',
            'app_secret' => '****',
            'default_graph_version' => 'v2.7',
        ]);

        $helper = $fb->getRedirectLoginHelper();

        $permissions = ['email'];
        $loginUrl = $helper->getLoginUrl('http://localhost/tshop/public/fbcallback', $permissions);
        //dd($fb);
        echo '<a href="' . $loginUrl . '">Log in with Facebook!</a>';
    }

    public function fbcallback() {

        $fb = new FacebookFacebook([
            'app_id' => '1780077285568634',
            'app_secret' => '625dc9eb7561f10bebc79ae2a1c96dca',
            'default_graph_version' => 'v2.7',
        ]);

        $helper = $fb->getRedirectLoginHelper();
        $_SESSION['FBRLH_state']=$_GET['state'];

        try {
            $accessToken = $helper->getAccessToken();
        } catch (FacebookExceptionsFacebookResponseException $e) {
            // When Graph returns an error
            echo 'Graph returned an error: ' . $e->getMessage();
            exit;
        } catch (FacebookExceptionsFacebookSDKException $e) {
            // When validation fails or other local issues
            echo 'Facebook SDK returned an error: ' . $e->getMessage();
            exit;
        }

        if (!isset($accessToken)) {
            if ($helper->getError()) {
                header('HTTP/1.0 401 Unauthorized');
                echo "Error: " . $helper->getError() . "n";
                echo "Error Code: " . $helper->getErrorCode() . "n";
                echo "Error Reason: " . $helper->getErrorReason() . "n";
                echo "Error Description: " . $helper->getErrorDescription() . "n";
            } else {
                header('HTTP/1.0 400 Bad Request');
                echo 'Bad request';
            }
            exit;
        }

        echo '<h3>Access Token</h3>';
        var_dump($accessToken->getValue());

// The OAuth 2.0 client handler helps us manage access tokens
        $oAuth2Client = $fb->getOAuth2Client();

// Get the access token metadata from /debug_token
        $tokenMetadata = $oAuth2Client->debugToken($accessToken);
        echo '<h3>Metadata</h3>';
        echo '<pre>';
        print_r($tokenMetadata);

// Validation (these will throw FacebookSDKException's when they fail)
        $tokenMetadata->validateAppId('1780077285568634'); // Replace {app-id} with your app id
// If you know the user ID this access token belongs to, you can validate it here
//$tokenMetadata->validateUserId('123');
        $tokenMetadata->validateExpiration();

        if (!$accessToken->isLongLived()) {
            // Exchanges a short-lived access token for a long-lived one
            try {
                $accessToken = $oAuth2Client->getLongLivedAccessToken($accessToken);
            } catch (FacebookExceptionsFacebookSDKException $e) {
                echo "<p>Error getting long-lived access token: " . $helper->getMessage() . "</p>nn";
                exit;
            }

            echo '<h3>Long-lived</h3>';
            var_dump($accessToken->getValue());
        }

        $_SESSION['fb_access_token'] = (string) $accessToken;

        /* Get user details from facebook */
        try {
            // Returns a `FacebookFacebookResponse` object
            $response = $fb->get('/me?fields=id,name,email', $accessToken);
        } catch (FacebookExceptionsFacebookResponseException $e) {
            echo 'Graph returned an error: ' . $e->getMessage();
            exit;
        } catch (FacebookExceptionsFacebookSDKException $e) {
            echo 'Facebook SDK returned an error: ' . $e->getMessage();
            exit;
        }

        echo '<hr>';

        $user = $response->getGraphUser();

        echo '<hr>';
        echo $user['name'];
    }

}