How to include (add) a Blueprint component to a c++ actor?

Question

unreal engine

There is a Blueprint component "FlatComponent" created on ActorComponent, it needs to be somehow added to the c ++ actor, which is called "FlatActor".

The question is how to do it?

I tried to add this to FlatActor.h:

UPROPERTY(VisibleAnywhere)
TSubclassOf<class UActorComponent> FlatCompClass;

UPROPERTY()
UActorComponent* FlatComp;

But then I don't know what to do with it.