First, navigate to the direction containing application.py. On a Mac, first run the following: export FLASK_APP=application.py and then export FLASK_DEBUG=1.

On a PC, first run set FLASK_APP=application.py and then set FLASK_DEBUG=1.

From that point, get Flask running using flask run. The above steps need to be re-done every time you open a new terminal window.

Pip is required to install these packages

1. pip install Flask
2. pip install flask_script
3. pip install flask_bootstrap
4. pip install flask_moment
5. pip install flask_wtf
6. pip install flask_login
7. pip install flask_sqlalchemy

Make sure you update the path of app.config['SQLALCHEMY_DATABASE_URI'] to where your computer stores the database.

https://pythonspot.com/flask-web-app-with-python/