hints: TDictionary<TDecodeHintType, TObject>;
l: TList<TBarcodeFormat>;
begin
if not Assigned(FScanManager) then
begin
hints := TDictionary<TDecodeHintType, TObject>.Create();
l:=TList<TBarcodeFormat>.Create;
l.Add(TBarcodeFormat.QR_CODE);
hints.Add(ZXing.DecodeHintType.POSSIBLE_FORMATS, l);
FScanManager := TScanManager.Create(TBarcodeFormat.QR_CODE, hints);
не тестил