unity. How to set constant camera resolution?

Question

C++ / C#

In general, there is such a problem: if the aspect ratio (or resolution, xs, how to call it correctly) changes, then the camera starts showing what it should not, how can you make it so that in the second screenshot you can’t see the level that is below ?
(Ignore buttons that don't fit a little)
Screenshot 1:

Screenshot 2:

Answer 1

https://docs.unity3d.com/Manual/FrustumSizeAtDista...