If you want a check to be activated only by a specific user, enter the recipient’s @username next to the amount while creating a check via inline mode (e.g. “@send $10 @durov Thank you”).
If the recipient has no username, choose Edit Restrictions in the check settings, then tap Set Recipient and forward any message from the user.
The user must has disabled anonymous forwarding in Telegram's ‘Privacy and Security’ settings.
Go to the desired check and navigate to the Edit Restrictions.
2. Select Set Recipient.
3. Send @username of the user. You can also forward any user's message into the chat with the bot.
