Integrity Error- Django - Part -2 _Signals

I am watching the Django series - Part -2 - Signals- Lesson 11 which is at the end of Designing and building the Orders API. After adding “post_save” by creating a signals file in the store app, I am unable to add a new user as shown in the video. I did everything as shown in the video, but I am getting an integrity error while adding a new user to the admin page. Please help me out.

Error:

IntegrityError at /admin/core/user/add/

(1062, “Duplicate entry ‘’ for key ‘store_customer.email’”)

Request Method: POST

|Django Version:|4.1.6|
|Exception Type:|IntegrityError|
|Exception Value:|(1062, “Duplicate entry ‘’ for key ‘store_customer.email’”)|
|Raised during:|django.contrib.auth.admin.add_view|

Are you adding a new customer, but using the same email as an existing customer? You can check it out in DataGrip.