TChromium (dcef3): как правильно сформировать POST запрос

function CreateField(const AValue: AnsiString): ICefPostDataElement;
begin
 Result := TCefPostDataElementRef.New;
 Result.SetToBytes(Length(AValue), PAnsiChar(AValue));
end;
 
//*****************************************
 
procedure POST(total, fee: integer);
var
 Header: ICefStringMultimap;
 Data: ICefPostData;
 Request: ICefRequest;
 Cook: ICefCookieManager;
begin
 Request := TCefRequestRef.New;
 Request.Url := '';
 Request.Method := 'POST';
 Request.Flags:=[UR_FLAG_ALLOW_CACHED_CREDENTIALS,UR_FLAG_ALLOW_COOKIES];
 
 Header := TCefStringMultimapOwn.Create;
 Header.Append('Host', '(...)');
 Header.Append('User-Agent', '(...)');
 Header.Append('Accept', '(...)');
 Header.Append('Accept-Language', '(...)');
 Header.Append('Accept-Encoding', '(...)');
 Header.Append('Content-Type', '(...)');
 Header.Append('Referer', '(...)');
 Header.Append('Content-Length', '(...)');
 Header.Append('Origin', '(...)');
 Header.Append('Connection', '(...)');
 Header.Append('Pragma', '(...)');
 Header.Append('Cache-Control', '(...)');
 
 Header.Append('Cookie',(...));
 ...
 Header.Append('Cookie',(...));
 
 Request.SetHeaderMap(Header);
 
 Data := TCefPostDataRef.New;
 Data.AddElement(CreateField('sessionid='+SessionID));
 Data.AddElement(CreateField('&currency=5'));
 Data.AddElement(CreateField('&subtotal='+inttostr(total-fee)));
 Data.AddElement(CreateField('&fee='+IntToStr(fee)));
 Data.AddElement(CreateField('&total='+IntToStr(total)));
 
 Request.PostData := Data;
 
 form1.Chromium1.Browser.MainFrame.LoadRequest(Request);
end;