How to implement registration and authorization on all pages of the site?

Question

Django

How to implement registration and authorization in Django on all pages of the site in modal windows ???
I tried to implement this via context_processors.py but ran into problems:
1. I can't differentiate between the POST request calls for the login form and the login form.
2. Since context_processors.py returns a dict, I can't validate the user and return a JsonResponse

So what Django tools should I use to implement my plan???