I am very new to Flask and trying to configure python-decouple to use .env variables. I am getting decouple.UndefinedValueError: APP_SETTINGS not found. Declare it as envvar or define a default value. when trying to run the server(macOS). The .env file is located in the root directory. Here is my code:

export SECRET_KEY=fdkjshfhjsdfdskfdsfdcbsjdkfdsdf
export DEBUG=True
export APP_SETTINGS=config.DevelopmentConfig
export DATABASE_URL=sqlite:///db.sqlite
export FLASK_APP=src
export FLASK_DEBUG=1

Give me suggest solution please ,