How to obtain Telegram chat_id for a specific user?

Question

How to obtain user chat_id in Telegram bot API? The documentation says:

Integer | Unique identifier for the message recipient — User or G

Answer 1

I created a bot to get User or GroupChat id, just send the /my_id to telegram bot @get_id_bot.

It does not only work for user chat ID, but also for group chat ID.

To get group chat ID, first you have to add the bot to the group, then send /my_id in the group.

Here's the link to the bot.