Why doesn't the django admin site add an entry section for the model?

Question

Django

The section for Advertisement does not appear on the site, although everything seems to be entered correctly.
There is a model file: model.py

from django.db import models


class Advertisement(models.Model):
    title = models.CharField(max_length=1000)
    description = models.CharField(max_length=1000, default='', verbose_name='Описание')
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    price = models.FloatField(verbose_name='Цена', default=0)
    views_count = models.IntegerField(verbose_name='Количество просмотров', default=0)
    status = models.ForeignKey('AdvertisementStatus', default=None, null=True, on_delete=models.CASCADE,
                               related_name='advertisements', verbose_name='Статус')

    def __str__(self):
        return self.title

    class Meta:
        db_table = 'advertisements'
        ordering = ['title']


class AdvertisementStatus(models.Model):
    name = models.CharField(max_length=100)

    def __str__(self):
        return self.name

And admin.py :

from django.contrib import admin
from .models import *


@admin.register(Advertisement)
class AdvertisementAdmin(admin.ModelAdmin):
    pass

Answer 1

default_app_config should be written

Answer 2

try like this
admin.site.register(Advertisement)

Answer 3

Is the application with this model definitely included in INSTALLED_APPS in the settings?

Answer 4

If you import a specific model? Have you already done reloading the application / hard reload in the browser, as I understand it? Although it should load without it
from .models import Advertisement