Line trace spread

I was looking at that but it looks confusing and im not sure how i would set it up

Like i havent looked at Static CORE_API so i dont know what it means or does and i dont know if i need to change the const& dir or ConeHalfAngleRad

static CORE_API FVector VRandCone(FVector const& Dir, float ConeHalfAngleRad);
static CORE_API FVector VRandCone(FVector const& Dir, float HorizontalConeHalfAngleRad, float VerticalConeHalfAngleRad);