Hey ​@Arman Shayan 

Try this guide: https://help.manychat.com/hc/en-us/articles/14281355805212-How-to-create-a-Telegram-automation-in-Manychat

Thanks for the response ​@rodrigo_silvano 

But this is an instruction on how to connect a telegram bot, and I need to offer the user to subscribe to a telegram channel and get something in return. How can I check subscription automatically?

​@Arman Shayan there's no native way to do that with Manychat.

You may be able to sort it out using Telegram's API, which is quite complete and well documented. But it'll take some coding and custom development.

Thank you so much 

Yes you can do it using Telegram API. I did it for my customers a lot.