YandexMaps API how to find the first waypoint leaving the polygon?

Question

API

Yandex.Map API v2+
There is a route A to B.
There is a polygon C.
Point A is always inside polygon C.
How to find the first point (coordinates) in the route A-B that is not included in polygon C?
in the old version 1 there was such a thing
polygon.getClosestPoint(point)
in version 2 there is such a thing:

myPolyline.geometry.getClosest(e.get('coordPosition'))

how to connect it with the polygon xs))