How to Install 3D Map Generator Terrain 1.4.2? (Photoshop Extension)

I downloaded what appears to be a valid Photoshop "Extension". But install instructions saw to install with Extension Manager which is now RIP. It also say I can use Terminal App -which I'm not conversant in. Below are the instructions in the Install PDF:

Perhaps this app has not been optimized for Photoshop 2018, and is incompatible. I have installed Plugins without issue, but have not encountered "Extensions" for some time. Anyone here using this app? Any suggestions for install? (Obviously I'm not an IT wiz)

Thanks

From the Install PDF:

OSX

Launch Terminal and run this command to open the install folder

(or open the folder by yourself):

open /Library/Application\Support/Adobe/CEP/extensions/

Navigate to your download folder > 01_installation and copy the

folder “3D_Map_Generator_Terrain” into the extensions folder.

Restart Photoshop. You will find the extension in the Photoshop menu:

Window > Extensions > 3D Map Generator - Terrain