To install FoliageTool, you must be using Unity 2022 (or newer).
FoliageTool uses the following packages as dependencies. These should install automatically when you install FoliageTool.
"com.unity.modules.terrain": "1.0.0",
"com.unity.mathematics": "1.2.6",
"com.unity.splines": "2.4.0",
"com.unity.editorcoroutines": "1.0.0"
Clone the repository into your Unity project's Packages
folder.
cd Packages/
git clone https://github.com/GeekBrony/FoliageTool.git
mv FoliageTool/ team.poni.foliage-tool/
The commands above clone the repository into a folder with the name of the package.
Once this process is done, Unity should recognize it as a valid package, and you should be ready to dive in!