How do I detect the game if running in editor?

Hello there, I’d like to print a run time message for lvl designers but I cannot find how to determine the game is running in editor. I tried the following code but it doesn’t work.

#if PlayMode_InEditorFloating
GEngine->AddOnScreenDebugMessage((-1, 5.0f, FColor::Red, TEXT(“destruction stage cannot be 0!”));

Any ideas?