python -m pip install --upgrade pip

admin

C:\Users\YUYUZ>python -m pip install --upgrade pip
Requirement already satisfied: pip in c:\program files\windowsapps\pythonsoftwarefoundation.python.3.9_3.9.1776.0_x64__qbz5n2kfra8p0\lib\site-packages (21.1.3)
Collecting pip
  Downloading pip-21.2.2-py3-none-any.whl (1.6 MB)
     |████████████████████████████████| 1.6 MB 1.1 MB/s
Installing collected packages: pip
  WARNING: The scripts pip.exe, pip3.9.exe and pip3.exe are installed in 'C:\Users\YUYUZ\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\Scripts' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
Successfully installed pip-21.2.2
WARNING: You are using pip version 21.1.3; however, version 21.2.2 is available.
You should consider upgrading via the 'C:\Users\YUYUZ\AppData\Local\Microsoft\WindowsApps\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\python.exe -m pip install --upgrade pip' command.

C:\Users\YUYUZ>