My question is: 
how to join my telegram bot to a telegram public channel that I am not administrator of it, and without asking the channel's admin to add my bot to the channel?
maybe the chatId of channel or thru link of channel?
Thank you in advance :)
edit------
I have heard that some people claim to do this join their bot to channels, and scrape data.
So if Telegram does not allow it, how can they do it? can you think of any work around?
Appreciate your time?
Till today, only the Channel Creator can add a bot (as Administrator or Member) to the Channel, whether public or private. Even the other Channel Administrators cannot add a normal member leave alone adding a bot, rather they can only post into the channel.
As far as joining the bot via the invite link, there is yet no such method in Bot API to do so. All such claims of adding the bot to a channel by non Creator are false.
How to join my Telegram Bot to PUBLIC channel