This got even easier with the recent release of version 1.66 (and later) of Nomad Sculpt. The newer versions support direct creation of depth maps (or “heightmaps”), which eliminates the need to use Blender. I know that is a stumbling point for a lot of people.
I made another short video with a walkthrough on how to do it in just Nomad Sculpt, optionally adjusting the dynamic range in a bitmap editor (Procreate, Photoshop and GIMP specifically covered).
TL;DW: There is a checkbox in the debug menu for “Heightmap” that will switch your view to a depth map. Render that out from a straight-on view. Optionally, use a bitmap editor to decompress the dynamic range.