You do not have same issue as Jimmy. he is talking of OBJ import and you are talking of VOX import. Please create your own thread next time.
By the way to do what you want, you just have to go in Model properties > OBJ > check "Optimized Mesh + texture" > OK > Export as OBJ > Done


Sorry, I went ...

I just experienced the same :P I have no experience in Cubik but wanted to use it to optimize and generate UVs for objects from MagicaVoxel, not sure where to begin looking :D I imported my object and then I can do nothing other then move my views around. There are certainly some quirks here I need ...