Followed everything mentioned in the readme of this repo.
In my mysite/requirements.txt I have:
fcm-django
coreapi
django-cors-headers
djangorestframework
django-sslserver
Django
six
urllib3
pyyaml
both servers frontend and backend are running smoothly. Granted permission for notiification on BRAVE BROWSER. But in the console I get this An "error occurred while retrieving token. AbortError: Registration failed - push service error"
error:

I even tried running the backend on ssl server but it does not work.
[EDIT]
I tried this on Chrome and got this error
