Add User Registration/Sign In/Password Reset to a Flask/Bootstrap driven website

I'm developing Dash/Plotly/Bootstrap dashboards (framework for building dashboards with python/pandas) and I'd like to add user registration around these pages. This project has 2 parts, first the registration and login functionality and the second phase is the integration into a payment processor to allow for paid subscriptions. Since Dash already uses Flask and I'm using Bootstrap in concert with it so I'd like the rest of the site developed in Flask and Bootstrap. I'm more of a self taught scripter than professional programmer, which is why I'd like this portion handled by someone with more experience and expertise.

Part 1 details:
*My Dash pages would be incorporated so that they are only reachable for signed in users.
*Requires password reset functionality via email with magic links
*Require a certain level of password complexity
*Agree to Terms of Service as part of the registration process
*Currently using Postgres as a database
*Only minimal theming in Bootstrap to match my Dash pages theme

Part 2
*Incorporate paid subscriptions via a payment processor (popular ecommerce service)
*Paid users would have access to certain premium Dash pages
*Paid users should have immediate access to the premium pages

Please quote for both parts. You should have experience building registration/login/password reset functionality in Flask. Also require good communication skills in English and code needs to be well documented.