INNEO is correct. However- some people have done the trick where you apply the displacement - export the model (effectively 'baking' in the displacement - ie. no longer editable displacement parameters) then reimport the baked mesh and apply a separate displacement.
This does lead to some issues - such as creating a really really heavy polygonal model - but it is entirely possible depending on what you're trying to do.
Personally - I like to apply my displacement in Blender (my modeling program of choice)- mostly because that is where I have always done it and am most comfortable there. But it's the same concept - the displacement is baked into the model and if I wanted, I could add a separate displacement while in Keyshot.
