401 Несанкционированный на Adyen API

Я пытаюсь произвести оплату в своей тестовой среде в Адиене с помощью curl, но по какой-то причине я продолжаю получать ответ 401 Несанкционированный. Я проверил учетные данные пользователя веб-службы десятки раз, но я уверен, что они верны. Когда я пытаюсь официальную библиотеку Adyen PHP Api (https://github.com/Adyen/adyen-php-api-library) Я получаю те же результаты. Я также попытался создать нового пользователя веб-службы, но безрезультатно. Кто-нибудь знает, что я делаю не так?

Код запроса:

<?php

$request = array(
"merchantAccount" => "MyWebsite",
"amount" => array(
"currency" => "EUR",
"value" => "199"),
"reference" => "TEST-PAYMENT-" . date("Y-m-d-H:i:s"),
"shopperIP" => "2.207.255.255",
"shopperReference" => "YourReference",
"billingAddress" => array(
"street" => "Simon Carmiggeltstraat",
"postalCode" => "1011DJ",
"city" => "Amsterdam",
"houseNumberOrName" => "6-60",
"stateOrProvince" => "NH",
"country" => "NL"),
"card" => array(
"expiryMonth" => "08",
"expiryYear" => "2018",
"holderName" => "Test Card Holder",
"number" => "4111111111111111",
"cvc" => "737"),
);

$json = json_encode($request);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://pal-test.adyen.com/pal/servlet/Payment/v25/authorise");
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC  );
curl_setopt($ch, CURLOPT_USERPWD, "xxxx:xxxx");
curl_setopt($ch, CURLOPT_POST, count($request));
curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER,array("Content-type: application/json"));

// things I tried
curl_setopt($ch, CURLOPT_USERAGENT,'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17');
curl_setopt($ch, CURLOPT_AUTOREFERER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);

$result = curl_exec($ch);

?>

Переменная $ result возвращает пустую строку.

Отклик:

*   Trying 91.212.42.153...
* Connected to pal-test.adyen.com (91.212.42.153) port 443 (#0)
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/certs/ca-certificates.crt
CApath: /etc/ssl/certs
* SSL connection using TLSv1.2 / ECDHE-RSA-AES128-GCM-SHA256
* ALPN, server did not agree to a protocol
* Server certificate:
*    subject: C=NL; ST=Noord-Holland; L=Amsterdam; O=Adyen B.V.; CN=*.adyen.com
*    start date: Jun 14 00:00:00 2016 GMT
*    expire date: Aug 13 23:59:59 2018 GMT
*    issuer: C=US; O=thawte, Inc.; CN=thawte SSL CA - G2
*    SSL certificate verify ok.
* Server auth using Basic with user 'xxxxx'
> POST /pal/servlet/Payment/v25/authorise HTTP/1.1
Host: pal-test.adyen.com
Authorization: Basic xxxxxx
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17
Accept: */*
Content-type: application/json
Content-Length: 465

* upload completely sent off: 465 out of 465 bytes
< HTTP/1.1 401 Unauthorized
< Date: Mon, 02 Apr 2018 19:58:11 GMT
< Server: Apache
< Set-Cookie: JSESSIONID=47E667BF9B585DC3BDF40F8D58493E23.test103e; Path=/pal; Secure; HttpOnly
* Authentication problem. Ignoring this.
< WWW-Authenticate: BASIC realm="Adyen PAL Service Authentication"< Content-Length: 0
< Content-Type: text/plain; charset=UTF-8
<
* Connection #0 to host pal-test.adyen.com left intact