Example Flask Authentication using SQLAlchemy, Flask-Login
Based on working through: https://www.digitalocean.com/community/tutorials/how-to-add-authentication-to-your-app-with-flask-login
Not only does this use Flask-Login, SQLAlchemy it is based on Flask BluePrints and is based on a "application factory” pattern.
Aim in addition to understanding the technology is to switch to using MariaDB, (not SQLLite) and use Bootstrap v5.2 for templates.