How can I protect my Telegram bot?

A bot running in privacy mode will not receive all messages that people send to the group . Instead, it will only receive: Messages that start with a slash ‘/’ (see Commands above) Replies to the bot’s own messages.

The only way is using a custom command like /password to send a password to the bot and then keep the chat id of the client (when password is correct of course …).2 Eyl 2017

To help your Telegram bot be as secure as possible, limit access to only the IPs Telegram is sending updates from . You can also limit IP access on the server side.