PHP SOAP WSDL协议

Can somebody tell me please how SOAP WSDL sets the protocol in WSDL uri? I really dont understand how it works but need to set up HTTPS in SOAP XML for request url. The XML generated by WSDL for request looks like:

<soapenv:Envelope 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" 
xmlns:bas="http://api.indexpodnikatela.sk/iris/basic">
   <soapenv:Header>
      <token xsi:type="xsd:string">XYZZZZZZ</token>
   </soapenv:Header>
   <soapenv:Body>
      <bas:findByIco soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
         <ico xsi:type="xsd:int">abcdefg</ico>
      </bas:findByIco>
   </soapenv:Body>
</soapenv:Envelope>

There is url http://api.indexpodnikatela.sk/iris/basic I suppose it is responsible for request. But I dont know how the HTTP protocol appears there. I send url in form api.indexpodnikatela.sk/iris/basic?wsdl to service without protocol (cause it does not work with protocol) and it generates me this XML. I dont know where it happens. It is like a black magic. It drives me crazy.... So the question is where php generates this XML and how to set up HTTPS in url? Thanks a lot for any help.