Make sure you have the latest version of Python available, at least python 3.12, and make PIP part of the install.

Decompress the cgplotter TAR file or Zip.

CD into the cgplotter directory .

in Linux it is probably easier to create and use a virtual environment as follow
Create a virtual environment for python using
python3 - m venv venv

Activate the virtual environment with
source venv/bin/activate

Deactivate with 
deactivate

install the requirements in the virtual environment using
pip install -r requirements.txt (or buildtools/requirements.txt)

create the exectutable using

pyinstaller linux.spec 

or

pyinstaller windows.spec
or if pyinstaller is not found
python -m PyInstaller windows.spec 

the executable will be in a holder "dist/cgplotter"

Use an IDE such as PyCharm to make changes to the code and test