Sending receipts on check-in with extension

[SilentResonance]

Hello,

thank you very much for the help with extensions a while ago.
Alf.io is a very useful peace of software.

In my current case, sending mails is working.
I am going to import attendees via CSV due to external questionaire tool usage.
After that, I can send tickets to all attendees and check them in at the venue.
Now my question is, whether it is possible to automatically send a receipt at check-in time. Directly after an attendee is checked in, he/she gets an e-mail with his/her receipt.
Is this possible via extension? I already found the ``TICKET_CHECKED_IN` event for an extension, which printing stuff to console.
As I know that this is a sandbox, I'm wondering, whether triggering sending a receipt to an attendee is possible.

Thanks in advance for any insights.