Questions about Basic Auth Implementation

I am using dash-auth (Basic Auth) in my dash app. I want to improve the login experience for the user and want to provide change password etc functionality.

For this, I wanted to convert the login dialog into a simple HTML login form with a link to change password. I tried to reverse engineer and explore the code in dash-auth module but didn't get much luck. Here are my primary questions

1. Where is the JS code which receives the username and password from login dialog and submit to server ?
2. Where is the code which sets the Authorization header before every request to the server?
3. At client side where are we storing the value set in Authorization header ?
4. Where is the code which renders the dialog for username and password.

Please let me know if anything else I would need in order to implement above use case or if there is a better existing implementation which I can reuse.

Thanks!

The issue names dash-auth's login dialog, JavaScript submission, Authorization header handling, and client-side storage as areas to investigate; start by tracing those paths in the dash-auth module. A contribution would need an agreed scope for an HTML login form, password-change link, and any server-side support before completion can be defined.