Does airflow_settings.yaml support environment variables?

Hi, does the airflow settings file support environment variables from the host machine?
For exemple below USER_PASS is an env variable on the local host environment.

airflow:
  connections:
    - conn_id: 'some_connection'
      conn_type: 'postgres'
      conn_host: 'some_host.com'
      conn_login: 'some_user'
      conn_password: ${USER_PASS}
      conn_port: 5439
      conn_schema: 'some_schema'

At the moment, it does not.

What about in the Docker file? something like this works if the $PASS variable is defined in the .env file:

ENV AIRFLOW__SMTP__SMTP_PASSWORD=$PASS

But using the same Dockerfile with deploy doesn’t seem to work.