How can I get BP class for c++?

right click on a actor in your content browser then click on “Copy Reference” (It will copy its path)

in the class.h

TSubclassOf<class AClass> ActorToSpawn

Class.cpp

#include "Engine.h"
#include "Engine/Blueprint.h"

static constructorHelpers::FObjectFinder<UBlueprint> type a name for your variable here( Text("past that path here"));

if (yourVariable.Succeeded())
{
  ActorToSpawn= (UClass*)yourVariable.Object->GeneratedClass;
}