How to create a bot that works only after subscribing to a telegram channel?

Question

Python

Good evening. I often come across bots that work only after you subscribe to a certain channel and I was wondering how to add such a function to the bot?
For example, on PyTelegramBotAPI or on Aiogram.
thanks in advance

Answer 1

At the beginning of the request processing chain, a check is made to see if the user is a channel subscriber or not...