Using Gnuboard DB with Django custom AUTH_USER_MODEL

settings.py

import os
import json

from django.core.exceptions import ImproperlyConfigured

# some settings
# ...
# ...

INSTALLED_APPS = [
    # ...
    'auth_app',
    # ...
]

AUTHENTICATION_BACKENDS = ['auth_app.auth.MyUserAuthBackend']

AUTH_USER_MODEL = (
    'auth_app.G5Member'
)

# ...
# othersettings...