procedure TClientSOAP.DoHTTPWebNodeBeforePost(
  const HTTPReqResp: THTTPReqResp; Data: Pointer);
var
  auth: String;
begin
  auth := 'Authorization: Basic ' + TNetEncoding.Base64.Encode(FUserName + ':' + FPassword);
  HttpAddRequestHeaders(Data, PChar(auth), Length(auth), HTTP_ADDREQ_FLAG_ADD);
end;