How to implement lighting in a 2D game?

Question

Unity

Is it possible to use Unity 3D lighting in 2D projects?
Using Lightmap for 2d graphics, let's say.
To what extent will it be optimal / non-optimal in terms of resources?
Maybe there are more rational ways to achieve realistic dynamic lighting?
I would appreciate any information. I found a couple of articles on Habré on this topic, but I decided to take an interest here as well.