The flask_mail module reads the configurations from the app, which is responsible for reading the config.py file. From file __ init __.py you can see how radsystems included the config and initialized the mail module. From what I have seen in the project, there is no code to ignore auth. From what I know, Google lets you generate an app password that you can use in mailing, but it does not accept your account password for SMTP. I can only point you to important files in your project, then you can do research on how to make it work.
{project root}\python-flask-api\app\__ init __.py line 22 → where mail module is initialized.
{project root}\python-flask-api\app\helpers\util.py line 247 → where radsystems mail function is defined.
{project root}\python-flask-api\venv\Lib\site-packages\flask_mail.py → where the flask mail module reside.
The Flask Mail Docs flask-mail — Flask-Mail 0.9.1 documentation (pythonhosted.org)