Why telegram bot can't download photos?

Question

Python

There is a line in the action_result method that should download the sent photo, but this does not happen. Why can this be?

available_code = ["прочитать", "закодировать"]


class Watermark(StatesGroup):
    waiting_for_action = State()
    waiting_for_result = State()


async def watermark_start(message: types.Message):
    keyboard = types.ReplyKeyboardMarkup(resize_keyboard=True)
    for name in available_code:
        keyboard.add(name)
    await message.answer("Выберите действие:", reply_markup=keyboard)
    await Watermark.waiting_for_action.set()


async def action_chosen(message: types.Message, state: FSMContext):
    if message.text.lower() not in available_code:
        await message.answer("Пожалуйста, выберите действие, используя клавиатуру ниже.")
        return
    await state.update_data(action=message.text.lower())
    await Watermark.next()
    await message.answer("Отправьте фото")


async def action_result(message: types.Message, state: FSMContext):
    if message.content_type != ContentType.PHOTO:
        await message.answer("Пожалуйста, отправьте фото")
        return
    await message.answer("тест")
    await message.photo[-1].download('test.png')
    await state.finish()


def register_handlers_watermark(dp: Dispatcher):
    dp.register_message_handler(watermark_start, commands="watermark", state="*")
    dp.register_message_handler(action_chosen, state=Watermark.waiting_for_action)
    dp.register_message_handler(action_result, state=Watermark.waiting_for_result)