How to get response from omnipay/paysera notifyUrl?

Question

I have some problem with notifyUrl. (Paysera/Omnipay) Im new in laravel so I'm wandering a lot at the moment. I want after payment activate my order, but cant get response... Here some code:

<?php

namespace App\Http\Controllers;

use Omnipay\Omnipay;

class PaymentController extends Controller
{
    private $gateway;

    public function __construct()
    {
        $this->gateway = Omnipay::create('Paysera');
        $this->gateway->setProjectId('****');
        $this->gateway->setPassword('****');
    }

    public function processPayment($orderId)
    {
        $response = $this->gateway->purchase(
            [
                'language' => 'ENG',
                'transactionId' => $orderId,
                'amount' => '10.00',
                'currency' => 'EUR',
                'returnUrl' => "http://localhost:8000/profile/payment/completed/{$orderId}",
                'cancelUrl' => "http://localhost:8000/cancel",
                'notifyUrl' => "http://localhost:8000/paysera/notify/{$orderId}",
            ]
        )->send();

        if ($response->isRedirect()) {
            $response->redirect();
        } else {
            echo $response->getMessage();
        }
    }

    public function notifyPayment($orderId)
    {
        $response = $this->gateway->acceptNotification();

        dd($response);
    }
}

enter image description here

i tried use acceptNotification(), but get this:

enter image description here

If im trying completePurchase()->send(), i get this:

Call to undefined method Omnipay\Paysera\Gateway::completePurchase()

How to get response after paying order?