How to create and modify a post-process on a camera in c++?

So, I want to be able to create a DepthOfField process in my game, but i want to access it and modify it by code. I can’t find any relevant example except for blueprints (and not well documented). The documentation doesn’t help me at all. I’m pretty new to UE4 and C++ but i’m really used to Unity and C# and i’m lost with this.

Regards