Please note that in order to use the ZBrush brushes you need to use at least ZBrush 4r8 p2. Also, the pack doesn’t include Substance Designer materials.
If can’t update to the necessary ZBrush version, add the alphas to a brush in your version of ZBrush and use the brushes. For ZBrush, it’s “easier and faster to just add one of the brushes, then import the PSD alphas and switch between the alphas rather than the brushes,” noted the artist.