Error: Can't find Python executable "C:\Users\arpit\AppData\Local\Programs\Python\Python39\python.EXE", you can set the PYTHON env variable. code example

Example: error: can't find python executable "python", you can set the python env variable.

apt-get update     
apt-get install python2.7    
ln -s /usr/bin/python2.7 /usr/bin/python