Everything else is done via the crown. It is also one of the rare perpetual calendars that can be set backwards or forwards, and it has an 8 day power reserve, so it’s much less of a hassle to maintain than your average perpetual.
Leap year indicator is on the back side, on the theory that you don’t need to look at it often. It’s the circular disc: Watchfinder did a great video on this watch a few years ago if you’re interested: https://m.