unable to create user account

Question

my create user work currectlly until i use a signal to create customer (user profile) after user created and i get error unable to create user account

# signal
from django.conf import settings
from django.db.models.signals import post_save
from django.dispatch import receiver

from store.models import Customer


@receiver(post_save, sender=settings.AUTH_USER_MODEL)
def create_customer_for_new_user(sender, instance, created, **kwargs):
   if created:
       Customer.objects.create(user=instance)

# app
from django.apps import AppConfig


class StoreConfig(AppConfig):
   default_auto_field = 'django.db.models.BigAutoField'
   name = 'store'

   def ready(self):
       import store.signals.handlers