can we use authenticate function without auth user creation code example

Example 1: django authenticate with email

from django.contrib.auth import get_user_model
from django.contrib.auth.backends import ModelBackend

class EmailBackend(ModelBackend):
    def authenticate(self, request, username=None, password=None, **kwargs):
        UserModel = get_user_model()
        try:
            user = UserModel.objects.get(email=username)
        except UserModel.DoesNotExist:
            return None
        else:
            if user.check_password(password):
                return user
        return None

Example 2: create login user django command

py manage.py  createsuperuser 
1=enter your userName
2=enter your email
3=enter your password
4=enter your password again 
5=for create user enter y (yes)