'pip' is not preinstalled in Windows. you need to install Python from https://www.python.org/downloads/ If you already installed python, set the PIP environment variable to C:\Users\<username>\AppData\Local\Programs\Python\Python36-32\Scripts\pip.exe
Check this one for an answer:
Python usually installs in a folder of your root drive like
and pip is located in subfolder
So you just have to add this last one to your global PATH environment variable.
Also note that by default, pip will install stuff under your user's Appdata/Local/...something folder in a specific directory, so if you are not using virtual environments, you may also need to add this folder to your path. (the exact folder name is usually printed in console when you actually run pip)
Make sure you read not only the first answer to that stackoverflow quesion.
pip comes pre-installed with Python. Are you sure you don't have pip installed on your system. Go to the command prompt and type 'pip -V'.
If it shows something similar to "pip is not recognized as a command", then follow https://phoenixnap.com/kb/install-pip-windows. Else pip is installed on your system.