Check out the official KitOps Pro 2 Installation video found here to get up and running: https://www.youtube.com/watch?v=vj0A2zeMN7o&ab_channel=ChippWalters

Installation is pretty smooth and quick by unzipping into your kPack path folder.

The inserts were modelled in Blender 3.x but they should work as they are mesh data and displacements (landscapes).  All inserts can be re-scalled, rotated and edited with Blender like any other shape.

Note: I use HardOps and this kPack workflow is enhanced by this addon, but not essential

Pro tip, if you are having issues with editing the inserts, use the KitOps Pro 2 button called convert to mesh and try again.