Virtual environments allow one to easily manage Python packages. To create virtual environments use the following command: pip install virtualenv Then while in the flask-auth working directory use the following command: virtualenv [Environment Name] The environment name can be whatever you want it to be. 

Activating/Deactivating your virtual environment varies depending on OS. Windows Activation/Deactivation: [Environment Name]\Scripts\activate [Environment Name]\Scripts\deactivate Linux Activation/Deactivation: source [Environment Name]/bin/activate source [Environment Name]/bin/deactivate 

With the virtual environment activated run the following command: pip install -r requirements.txt After that all you need to do is use the following command: flask run This spins up your application on localhost:5000 by default.