Why might a request to the Yandex.Checkout API not work?

Question

1C-Bitrix

Hello. Making a request with code

use YandexCheckout\Client;

$client = new Client();
$client->setAuth('.....', '.....');
$payment = $client->createPayment(
    array(
        'amount' => array(
            'value' => 6.0,
            'currency' => 'RUB'
        ),
        'confirmation' => array(
            'type' => 'redirect',
            'return_url' => 'https://site.ru/payment/index.php',
        ),
    ),
    uniqid('123', true)

Of course, instead of dots id with a key I substitute. But I get an error like "Class 'YandexCheckout\Client' not found (0)". I filled everything in the payment system settings, except for the storefront...

Answer 1

Are you just executing this code? And where did you get that it is in Bitrix?
Where are you connecting the class?