Colcon not installing from running pip colcon-common-extensions

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I am trying to use colcon to build by ROS2 package and powershell always returns

colcon : The term 'colcon' is not recognized as the name of a cmdlet, function, script file, or operable program.
Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1
+ colcon
+ ~~~~~~
    + CategoryInfo          : ObjectNotFound: (colcon:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

This is despite the fact that I have installed colcon correctly to the best of my knowledge. Here is the output I get from running pip install -U colcon-common-extensions

pip install -U colcon-common-extensions
Requirement already satisfied: colcon-common-extensions in c:\python38\lib\site-packages (0.2.1)
Requirement already satisfied: colcon-defaults in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.5)
Requirement already satisfied: colcon-notification in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.13)
Requirement already satisfied: colcon-powershell in c:\python38\lib\site-packages (from colcon-common-extensions) (0.3.6)
Requirement already satisfied: colcon-ros in c:\python38\lib\site-packages (from colcon-common-extensions) (0.3.21)
Requirement already satisfied: colcon-metadata in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.5)
Requirement already satisfied: colcon-output in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.12)
Requirement already satisfied: colcon-package-information in c:\python38\lib\site-packages (from colcon-common-extensions) (0.3.3)
Requirement already satisfied: colcon-library-path in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.1)
Requirement already satisfied: colcon-parallel-executor in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.4)
Requirement already satisfied: colcon-python-setup-py in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.7)
Requirement already satisfied: colcon-recursive-crawl in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.1)
Requirement already satisfied: colcon-core in c:\python38\lib\site-packages (from colcon-common-extensions) (0.6.1)
Requirement already satisfied: colcon-cmake in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.26)
Requirement already satisfied: colcon-package-selection in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.10)
Requirement already satisfied: colcon-devtools in c:\python38\lib\site-packages (from colcon-common-extensions) (0.2.2)
Requirement already satisfied: colcon-test-result in c:\python38\lib\site-packages (from colcon-common-extensions) (0.3.8)
Requirement already satisfied: coloredlogs in c:\python38\lib\site-packages (from colcon-core->colcon-common-extensions) (15.0)
Requirement already satisfied: pytest in c:\python38\lib\site-packages (from colcon-core->colcon-common-extensions) (6.2.3)
Requirement already satisfied: pytest-rerunfailures in c:\python38\lib\site-packages (from colcon-core->colcon-common-extensions) (9.1.1)
Requirement already satisfied: EmPy in c:\python38\lib\site-packages (from colcon-core->colcon-common-extensions) (3.3.4)
Requirement already satisfied: setuptools>=30.3.0 in c:\python38\lib\site-packages (from colcon-core->colcon-common-extensions) (54.2.0)
Requirement already satisfied: pytest-cov in c:\python38\lib\site-packages (from colcon-core->colcon-common-extensions) (2.11.1)
Requirement already satisfied: pytest-repeat in c:\python38\lib\site-packages (from colcon-core->colcon-common-extensions) (0.9.1)
Requirement already satisfied: distlib in c:\python38\lib\site-packages (from colcon-core->colcon-common-extensions) (0.3.1)
Requirement already satisfied: PyYAML in c:\python38\lib\site-packages (from colcon-defaults->colcon-common-extensions) (5.4.1)
Requirement already satisfied: pywin32 in c:\python38\lib\site-packages (from colcon-notification->colcon-common-extensions) (300)
Requirement already satisfied: colcon-pkg-config in c:\python38\lib\site-packages (from colcon-ros->colcon-common-extensions) (0.1.0)
Requirement already satisfied: catkin-pkg>=0.4.14 in c ...