Bot messagewhere you can greet the user and start the conversation:
known_user_flag, the bot can check whether it has talked to this specific user before, and redirect them to a personalised introduction.
1, the bot knows that there has been a conversation with this user before, otherwise this variable would be empty. Now the user can be redirected to an introduction message for returning users.
known_user_flagdoes not exist, the user is a new user and should be redirected to an introduction for new users. At the same time, you should set the
1because now, the user is not new anymore.