When trying to install a package via pip, it's recommended to invoke pip as a module: python -m pip install your_package.
Why would we use python -m pip instead of pip?
Invoking pip as a module ensures you know which pip you're using. This is helpful if you have multiple Python versions. You always know which Python version you're installing packages to.
Note
The exact python command you invoke can vary. It may be python3 or py, ensure it's correct for your system.