When I send this request I receive this error: The endpoint reference (EPR) for the Operation not found is /services/OrderWebService?wsdl=&tenant=virtual and the WSA Action = null

<?php

$curl = curl_init();

curl_setopt_array($curl, array(
CURLOPT_URL => "https://app.onebillsoftware.com/services/OrderWebServicewsdl
=&tenant=virtual",

CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => "<soap:Envelopexmlns:soap=\"http://www.w3.org/2003/05/soap-envelope\"  xmlns:ser=\"http://service.order.webservice.onebill.tarshan.com\"  xmlns:xsd=\"http://request.order.webservice.onebill.tarshan.com/xsd\">\r\n    <soap:Header/>\r\n   <soap:Body>\r\n      <ser:getOrder>\r\n         <!-- Optional:-->\r\n         <ser:getOrderRequest>\r\n            <!--Optional:-- >\r\n            <xsd:orderNumber>OR8126</xsd:orderNumber>\r\n          </ser:getOrderRequest>\r\n      </ser:getOrder>\r\n    </soap:Body>\r\n</soap:Envelope>",
 CURLOPT_HTTPHEADER => array(
 "authorization: Basic ZHNjb3R0QHZ0Z3VzLmNvbTpBa29vc3dhZzQxOQ==",
 "cache-control: no-cache",
 "postman-token: 2a90fa5f-a68c-39d2-dadb-bf39424a7535",
 "tenant: virtual"
 ),
 ));

$response = curl_exec($curl); $err = curl_error($curl);

curl_close($curl);

 if ($err) {
 echo "cURL Error #:" . $err;
} else {
echo $response;

http://php.net/manual/en/curl.examples-basic.php

$ch = curl_init("http://www.example.com/");

That was one google search.