For DRF, it is better to use the SessionAuthentication

from rest_framework.authentication import SessionAuthentication


class ApproveOrDeclineUserView(APIView):
    authetication_classes = (SessionAuthentication, )

Or use directly for whole endpoints:

# In your DRF settings
REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': [
        'rest_framework.authentication.SessionAuthentication',
    ]
}

And don't forget to remove decorator - @method_decorator