how add header to request

hello!

how I can add to my request header? if i'm using web service.

s ws =##class(Data.SOAP.Base.Ws.ServiceSoap).%New()s resp=##class(%XML.DataSet).%New()
s resp = ws.Getaccblocks(IIN)

i need send request like bellow

<?xml version="1.0" encoding="UTF-8" ?>
<SOAP-ENV:Envelope
    xmlns:SOAP-ENV='http://schemas.xmlsoap.org/soap/envelope/'
    xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
    xmlns:s='http://www.w3.org/2001/XMLSchema'>

<header>
.....
</header>
​
    <SOAP-ENV:Body>
        <Get_acc_blocks
            xmlns="http://microsoft.com/webservices/">
            <IIN xsi:type="s:string">123456789</IIN>
        </Get_acc_blocks>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

Method Getaccblocks(IIN As %String) As %XML.DataSet(XMLNAME="Get_acc_blocksResult") [ Final, ProcedureBlock = 1, SoapBindingStyle = document, SoapBodyUse = literal, WebMethod ]{Quit ..WebMethod("Get_acc_blocks").Invoke($this,"http://microsoft.com/webservices/Get_acc_blocks",.IIN)}