See this NKS onboarding video for Novation products.
You will need to use two NKS templates for the Launchkey Mk3's pots and pads, which are available in Components:
Launchkey Mk3 Components Guide
If you are unfamiliar with the custom modes on your Launchkey, please refer to pages 34 and 35 of the Launchkey MK3's user guide.