CodeIgniter Omnipay Przelewy24 gateway library | failed to open stream: autoload.php

Question

For CL3 I use omnipay library:

https://github.com/thephpleague/omnipay

for Przelewy24:

https://github.com/TicketSwap/omnipay-przelewy24

Both I install via composer and I see in:

vendor/omnipay
vendor/ticketswap

Fallowing to documentation I created

public_html/application/views/cart/payment_methods/_przelewy24.php

this file contains:

require_once  __DIR__ . '/vendor/autoload.php';

use Omnipay\Omnipay;

/** @var \Omnipay\Przelewy24\Gateway $gateway */
$gateway = Omnipay::create('Przelewy24');

$gateway->initialize([
    'merchantId' => 'YOUR MERCHANT ID HERE',
    'posId'      => 'YOUR POS ID HERE',
    'crc'        => 'YOUR CRC KEY HERE',
    'testMode'   => true,
]);

and now when I select this payment option I get:

Severity: Warning

Message: require_once(/public_html/application/views/cart/payment_methods/vendor/autoload.php): failed to open stream: No such file or directory

Filename: payment_methods/_przelewy24.php

Line Number: 4

When I deleted

require_once  __DIR__ . '/vendor/autoload.php';

then I get:

Type: Error

Message: Class 'Omnipay\Omnipay' not found