router.post("/register", upload.single('image'), function (req, res, next)
{
  var url = 'http://smeapps.mobitel.lk:8585/EnterpriseSMSV2/EnterpriseSMSWS?wsdl';

  var session = {username: 'username', password: 'password'}

  soap.createClient(url, function(err, client)
  {
    if(err)
    console.log(err)
    client.createSession(session, function(err, result)
    {
      console.log(result);
    });

  })
})

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ws="http://ws.esms.mobitel.lk/">
   <soapenv:Header/>
   <soapenv:Body>
      <ws:createSession>
         <!--Optional:-->
         <arg0>
            <!--Optional:-->
            <customer>12</customer>
            <!--Optional:-->
            <id>12</id>
            <!--Optional:-->
            <password>password</password>
            <!--Optional:-->
            <username>username</username>
         </arg0>
      </ws:createSession>
   </soapenv:Body>
</soapenv:Envelope>

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://ws.esms.mobitel.lk/">
   <SOAP-ENV:Body>
      <ns1:createSessionResponse>
         <return>
            <expiryDate>2018-10-04T06:24:25+05:30</expiryDate>
            <isActive>true</isActive>
            <sessionId>761033662786</sessionId>
            <user>0</user>
         </return>
      </ns1:createSessionResponse>
   </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

console.log(JSON.stringify(result))