This project uses kivymd for the UI part some old python packages which are deprecated and are maintained no more. but with proper set up the full functionality can be achieved. The bluetooth package used here is pybluez package which is based upon bluez, (You can google for more) is an old package which is not maintained anymore and sometimes difficult to install on the newer python versions.
WINDOWS: In order to install pybluez in windows machine, (that's how i achieved it) use python 3.7 and "pip install pyblez". please note, in my cases, i tried installing pybluez on other newer versions of python (3.9+) but always encounter errors regarding "wheels".
UBUNTU: Install/update bluetooth drivers before installing pybluez.