Run the editor from VC++ in the dx12 mode

Hi. Any idea how to run the editor from Visual Studio in the dx12 mode? I’ve tried to add the -dx12 argument to my game project → properties → Debugging → Command Arguments but the editor keeps starting in the dx11 mode. I’ve succesfully launched the dx12 editor several times from the Launcher so I know my machine is dx12 ready. Thanks :-).