How to catch the balloon opening event on Yandex Maps?

Question

Yandex maps

We need a simple example of how to throw an alert (Something), by clicking on a mark on the map while opening its balloon.
Found https://tech.yandex.ru/maps/doc/jsapi/2.0/ref/refe...
But it's not clear how to use it.
Only I don’t need to open it (it’s already opening now), but execute my code at the time of opening

Answer 1

You are not looking there. It is necessary not to wait for the balloon to open, but to cling to what starts to open it - clicking on the map or button, etc.
For example, placemarker has a balloonopen event.