<pyenv / dir>

    requirements.txt

pip install <pkg> >> requirements.txt

    main.py

from flask import Flask
app = Flask(__name__)

    config.py

app.config.from_object('config')

    instance/config.py

app = Flask(__name__, instance_relative_config=True)
app.config.from_pyfile('config.py')

 #SECRET_KEY in onfig.py

    SECRET_KEY =
    STRIPE_API_KEY =
    SQLALCHEMY_DATABASE_URI=

    ap_home/

                  __init__.py
                  models.py
                  views.py
                  templates/
                  static/ 

    config/<configname>.py

 app.config.from_envvar(‘ap_config_file’) #abs path of config file

#start ap from hosting
start.sh
ap_config_file=/<path>/<configname>.py
python main.py