I want the bot to replace the photo of the group, but the error AttributeError: 'NoneType' object has no attribute 'photo' appears, what should I change in the code?

Question

Python

I watch a course on creating telegram bots, I take a code from it, I need a person to send a photo, forward it, but at the same time write the /set_photo command, and the photo of the group is replaced, but when I enter it, I get an error, everything works in the teacher

import io

from aiogram import types
from aiogram.dispatcher.filters import Command

from filters import AdminFilter
from loader import dp


@dp.message_handler(Command('set_photo'), AdminFilter())
async def set_photo_groups(message: types.Message):
    source_message = message.reply_to_message
    photo = source_message.photo[-1]
    photo = await photo.download(destination=io.BytesIO())
    input_file = types.InputFile(path_or_bytesio=photo)
    await message.chat.set_photo(photo=input_file)

AttributeError: 'NoneType' object has no attribute 'photo'

Answer 1

You need to read about the state machine, or state machine. In aiogram, all this is very well implemented.
So you can describe the process of replacing a photo in a chat.