When I change company_name to company in Contact model

Issue with in admin panel

AttributeError at /admin/website/contact/

‘Contact’ object has no attribute ‘company_name’

Request Method: GET
Request URL: http://127.0.0.1:8000/admin/website/contact/
Django Version: 5.1.1
Exception Type: AttributeError
Exception Value: ‘Contact’ object has no attribute ‘company_name’
Exception Location: C:\Users\Baxti\Desktop\Django-CRM\website\models.py, line 182, in str
Raised during: django.contrib.admin.options.changelist_view

my contact model after change
company = models.ForeignKey(‘Account’, on_delete=models.SET_NULL, null=True, blank=True, related_name=‘contact_set’)

before
company_name = models.CharField(max_length=100, blank=True, null=True)

I found bug

	def __str__(self):
		return f"{self.first_name} {self.last_name} ({self.company_name})"

here company_name to change company