调用Striga沙箱API创建用户时出现HTTP 404 Not Found错误

今日早间曾咨询过链接相关错误，代码逻辑本身无问题，但当前POST请求出现新错误：向Striga沙箱环境的用户创建接口https://www.sandbox.striga.com/api/v1/user/create发送POST请求时，返回HTTP 404 Not Found错误，响应详情如下：

HTTP/1. 1 404 Not Found Date: Thu, 21 Sep 2023 15:39:13 GMT Content-Type: text/html; charset=utf-8 Connection: close x-xss-protection: 1; mode=block x-content-type-options: nosniff referrer-policy: no-referrer-when-downgrade content-security-policy: default-src 'self' http: https: data: blob: 'unsafe-inline'; frame-ancestors 'self'; permissions-policy: interest-cohort=() strict-transport-security: max-age=15552000; includeSubDomains; preload CF-Cache-Status: DYNAMIC Server: cloudflare CF-RAY: 80a3664c1b5158a8-IAD alt-svc: h3=":443"; ma=86400.

页面下方显示典型的404 Not Found提示。已尝试调整请求头、链接等，但API请求必须使用该链接，代码逻辑看似无误，相关代码如下：

require_once 'vendor/autoload.php';

use GuzzleHttp\Client;
use GuzzleHttp\Psr7;
use GuzzleHttp\Exception\ClientException;

if ($_SERVER['REQUEST_METHOD'] === 'POST') {

   $client = new Client(['base_uri' => 'https://www.sandbox.striga.com/api/v1/']);
   $SANDBOX_API_SECRET = '9YiaEuslYPQEjnCM5Ve1NyirgdMovwaaYJekhaWodVAp=';
   $method = 'POST';
   $body = ["mobile" => ["countryCode" => "+34", "number" => "644147933"], "dateOfBirth" => ["year" => 1999, "month" => 10, "day" => 6], "address" => ["addressLine1" => "Calle Bahía de Cádiz 2", "city" => "Sevilla", "postalCode" => "41009", "state" => "Sevilla", "country" => "España"], "firstName" => "Daniel", "lastName" => "González Pitt", "ipAddress" => "79.116.138.131", "email" => "danielgonzalez@gmail.com", "occupation" => "PUBLIC_SECTOR_ADMINISTRATION", "sourceOfFunds" => "FAMILY_SAVINGS", "sourceOfFundsOther" => "Descripción del sourceoffound", "selfPepDeclaration" => true, "purposeOfAccount" => "CARD_INSIDE_EEA", "purposeOfAccountOther" => "Descripción muy corta de purpose", "expectedOutgoingTxVolumeYearly" => "BETWEEN_1000_AND_5000_EUR", "expectedIncomingTxVolumeYearly" => "BETWEEN_1000_AND_5000_EUR", "placeOfBirth" => "ESP"];
   $TEST_ENDPOINT = '/user/create';

   function calcSig($body) {
      global $SANDBOX_API_SECRET, $method, $TEST_ENDPOINT;

      $mstime = floor(microtime(true) * 1000);
      $hmac = $mstime;
      $hmac .= $method;
      $hmac .= $TEST_ENDPOINT;

      $contentHash = md5(json_encode($body));
      $hmac .= $contentHash;

      $hmac = hash_hmac('sha256', $hmac, $SANDBOX_API_SECRET);

      $auth = 'HMAC ' . $mstime . ':' . $hmac;
      return $auth;
   }

   $headers = [
      'authorization' => calcSig($body),
      'api-key' => 'DhiZ4KSXXF4iJ4vbRieLO7SAHQ63rytSBRISGCwjLuo=',
      'Content-Type' => 'application/json',
   ];

   //echo print_r($headers);
   try {
      $response = $client->request('POST', '/user/create', [
         'headers' => $headers,
         'json' => $body
      ]);    
      //echo $response->getBody();
   } catch (ClientException $e) {
     // echo Psr7\Message::toString($e->getRequest());
      echo Psr7\Message::toString($e->getResponse());
   }


} else {
   echo 'Not access';
}

现寻求该404错误的原因及解决办法。

内容的提问来源于stack exchange，提问作者Daniel González Pitt