如何使用php连接wsdl api

Here is my code, and I can't figure out why it's not working.

$soapUrl = "http://airarabia.isaaviations.com/webservices/services/AAResWebServices?wsdl";

$xml_post_string = '<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><soap:Header><wsse:Security soap:mustUnderstand="1" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"><wsse:UsernameToken wsu:Id="UsernameToken-17855236" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"><wsse:Username>xxx</wsse:Username><wsse:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText">xxx</wsse:Password></wsse:UsernameToken></wsse:Security></soap:Header><soap:Body xmlns:ns2="http://www.opentravel.org/OTA/2003/05"><ns2:OTA_AirAvailRQ EchoToken="11868765275150-1300257933" PrimaryLangID="en-us" SequenceNmbr="1" Target="LIVE" TimeStamp="2018-10-08T11:39:35" Version="20061.00"><ns2:POS><ns2:Source TerminalID="Farhath/Farhath"><ns2:RequestorID ID="WSBENZTRAVELS" Type="4" /><ns2:BookingChannel Type="12" /></ns2:Source></ns2:POS><ns2:OriginDestinationInformation><ns2:DepartureDateTime>2018-10-30T00:00:00</ns2:DepartureDateTime><ns2:OriginLocation LocationCode="CMB" /><ns2:DestinationLocation LocationCode="RUH" /></ns2:OriginDestinationInformation><ns2:OriginDestinationInformation><ns2:DepartureDateTime>2018-11-30T00:00:00</ns2:DepartureDateTime><ns2:OriginLocation LocationCode="RUH" /><ns2:DestinationLocation LocationCode="CMB" /></ns2:OriginDestinationInformation><ns2:TravelerInfoSummary><ns2:AirTravelerAvail><ns2:PassengerTypeQuantity Code="ADT" Quantity="1" /></ns2:AirTravelerAvail></ns2:TravelerInfoSummary></ns2:OTA_AirAvailRQ></soap:Body></soap:Envelope>';

$headers = array(

"Host: airarabia.isaaviations.com",
"Content-Type: application/soap+xml; charset=utf-8",
"Content-Length: ".strlen($xml_post_string)
); 

$url = $soapUrl;

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $xml_post_string);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

$response = curl_exec($ch); 
curl_close($ch);

$response1 = str_replace("<soap:Body>","",$response);
$response2 = str_replace("</soap:Body>","",$response1);

$parser = simplexml_load_string($response);

print_r($parser);

I am able to connect to the API, but couldn't get a result.

Do you have any idea, any solution ?