UV-Packer for Blender consists of 2 components that need to be installed
separately: The UV-Packer for Blender addon that provides the user interface in
Blender and the corresponding program that performs the packing.

This archive contains the add-on for Blender. It can be installed through the
Add-ons section in Blender's preferences.

In order to use the packing functionality the UV-Packer for Blender executable
must be placed into the same directory the addon is installed into.

You can download the executable at https://www.uv-packer.com/blender/

You can find the documentation for UV-Packer with more information about the
installation and usage here:
https://doc.uv-packer.com