$env:FLASK_APP = "x.py" --> set the flask app to run
$env:FLASK_RUN_PORT = xxxx --> set the port to run on
$env:FLASK_ENV = "development" --> set the environment to run in
python -m venv venv --> create a virtual environment I
pipenv install --> create a virtual environment II
pipenv shell --> enter the virtual environment
pipenv install x --> install x in the virtual environment