old_contents: from django import forms
  from django.contrib.auth import get_user_model
  
  
  class AdminUserModelForm(forms.ModelForm):
      class Meta:
          model = get_user_model()
          fields = ('username', 'first_name', 'last_name', 'email')
  
new_contents: from django import forms
  from django.contrib.auth.models import User
  
  
  class AdminUserModelForm(forms.ModelForm):
      class Meta:
          model = User
          fields = ('username', 'first_name', 'last_name', 'email')
  
subject: Update admin_forms.py