How to make the bot write to the user when opening the Bitrix24 chat?

Question

1C-Bitrix

There is such a task, you need to create a bot for open Bitrix24 lines, like a Privat24 assistant bot.
Everything seems to be clear except how to call the bot when the user clicks on the chat, that is, not at the first message, but precisely when entering the chat. So that the bot immediately sends the menu. It works inside Bitrix, but not in open lines (.
Maybe someone has come across, or just knows the Bitrix API well, I will be grateful for any help

Answer 1

https://helpdesk.bitrix24.ru/open/6194339/ - you can see the possibilities here, and do it based on the "greetings"