c# write into existing XmlDocument from specflow table or dictionary

Question

I am trying to find a solution to read xml(wsdl) from a soap api so my test will be dynamical (not break if the xml structure has been changed) and add my values to this xml to send it as a request.

from the Speclow tables I could create my dictionary and I got the service xml as welll per operation

but how can I write my values into the XmlDocument ?

Thanks for the help.

public static XmlDocument GetRequestByData(Table createRequestTable, XmlDocument soapXML)
    {
        Dictionary<string, string> myDictionary = TableExtensions.ToDictionary(createRequestTable);

        XmlDocument requestXML = new XmlDocument();

        soapXML[] = myDictionary[];



        return requestXML;
    }