Telegram bot. Private messages to group members

Question

There is a public telegram chat. I want to make it so that when a user joins a chat group, the bot will send that user a private message.

I checked the technical capabilities and realized that this cannot be done, but I could be wrong. To implement this feature, the user must run this bot, then such an opportunity will appear.

Question. How to make it so that before joining a chat group, a person has to launch a bot?

Answer 1

First, you can get an array new_chat_members of new users in the chat from Message. Then you can send a Message with button (InlineKeyboardButton). This button has a switch_inline_query_current_chat field. That's what you need.