Where did calendar come from: "Found in programs" on mac?

Question

Calendar

Good afternoon,
I started receiving notifications from the calendar for events unknown to me.
I looked at the calendar, found a new one, called "Found in programs."

More like spam,

Who knows how to restrict the access of programs to the calendar and find out what kind of software creates these events?
Thank you.

Answer 1

I just deleted this calendar. The problem is gone.
Find out what kind of muck - did not. I would be grateful if you find a reptile.