django-allauth自定义注册表单在添加新用户时在管理页面中抛出错误。“CustomUserForm”对象没有属性“instance”

from django import forms
from django.contrib.auth.forms import UserCreationForm
from django.contrib.auth import get_user_model

class CustomUserCreationForm(UserCreationForm):
    class Meta:
        model = get_user_model()
        fields = ('username', 'email')

from django.contrib.auth.models import AbstractUser, BaseUserManager
from django.db import models

class CustomUserManager(BaseUserManager):
    def create_user(self, username, email, password=None):
        # 创建用户逻辑

class CustomUser(AbstractUser):
    objects = CustomUserManager()

AUTH_USER_MODEL = 'your_app.CustomUser'

from django.contrib import admin
from django.contrib.auth.admin import UserAdmin
from .models import CustomUser
from .forms import CustomUserCreationForm

class CustomUserAdmin(UserAdmin):
    add_form = CustomUserCreationForm
    model = CustomUser
    # 其他自定义配置

admin.site.register(CustomUser, CustomUserAdmin)