apt-get install python3-pip python3-dev python3-venv
Above line is for Linux Ubuntu. It may vary for your OS
python3 -m venv venv
source venv/bin/activate
pip3 install --upgrade -r requirements.txt
if __name__ == '__main__':
app.run(port=4000)
or
if __name__ == '__main__':
app.run(host="0.0.0.0", port=4000)
App with explicit host is visible from network
gunicorn --bind 127.0.0.1:4400 --workers=2 wsgi:app
or
gunicorn -b 0.0.0.0:4400 -w=2 wsgi:app