install xlaunch or xquartz.
install pip
download this: https://bootstrap.pypa.io/get-pip.py
cd C:\Program Files\Autodesk\Maya2018\bin\
C:\Program Files\Autodesk\Maya2018\bin> mayapy get-pip.py
install ptvsd
C:\Program Files\Autodesk\Maya2018\Python\Scripts>pip --version
pip 20.2.3 from c:\program files\autodesk\maya2018\Python\lib\site-packages\pip (python 2.7)
C:\Program Files\Autodesk\Maya2018\Python\Scripts> pip install ptvsd