Djangoda admin sayfasi hatasi

Djangoda serveri calistiriyorum ve servere,admin paneline giris yapa biliyorum.ama models i import etdigimde servere giremiyorum.lutfen biri yardim etsin.
Hata:

(sanal_ortam) C:\Users\AZE\Desktop\blogum\sitem>python manage.py runserver
Watching for file changes with StatReloader
Performing system checks...

System check identified no issues (0 silenced).
June 17, 2020 - 20:14:13
Django version 3.0.7, using settings 'sitem.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.
[17/Jun/2020 20:14:28] "GET / HTTP/1.1" 200 16430
[17/Jun/2020 20:14:35] "GET /admin/ HTTP/1.1" 200 3080
C:\Users\AZE\Desktop\blogum\sitem\posts\admin.py changed, reloading.
Watching for file changes with StatReloader
Performing system checks...

System check identified no issues (0 silenced).
June 17, 2020 - 20:24:24
Django version 3.0.7, using settings 'sitem.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.
C:\Users\AZE\Desktop\blogum\sitem\posts\admin.py changed, reloading.
Watching for file changes with StatReloader
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "c:\users\aze\appdata\local\programs\python\python38\lib\threading.py", line 932, in _bootstrap_inner
    self.run()
  File "c:\users\aze\appdata\local\programs\python\python38\lib\threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\utils\autoreload.py", line 53, in wrapper
    fn(*args, **kwargs)
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\core\management\commands\runserver.py", line 109, in inner_run
    autoreload.raise_last_exception()
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\utils\autoreload.py", line 76, in raise_last_exception
    raise _exception[1]
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\core\management\__init__.py", line 357, in execute
    autoreload.check_errors(django.setup)()
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\utils\autoreload.py", line 53, in wrapper
    fn(*args, **kwargs)
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\apps\registry.py", line 122, in populate
    app_config.ready()
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\contrib\admin\apps.py", line 24, in ready
    self.module.autodiscover()
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\contrib\admin\__init__.py", line 26, in autodiscover
    autodiscover_modules('admin', register_to=site)
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\utils\module_loading.py", line 47, in autodiscover_modules
    import_module('%s.%s' % (app_config.name, module_to_search))
  File "c:\users\aze\appdata\local\programs\python\python38\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "C:\Users\AZE\Desktop\blogum\sitem\posts\admin.py", line 6, in <module>
    admin.site.Register(postmodel)
  File "C:\Users\AZE\Envs\sanal_ortam\lib\site-packages\django\utils\functional.py", line 225, in inner
    return func(self._wrapped, *args)
AttributeError: 'AdminSite' object has no attribute 'Register'

(CMD)

admin.py ye boyle import etdim:

from django.contrib import admin
from .models import postmodel

# Register your models here.

admin.site.Register(postmodel)

(postmodel, olusturdugum classin ismi)

@admin.register(postmodel) şeklinde dener misiniz?

ilginiz icin tesekkurler.artik cozdum:)

yardımım dokunduysa ne mutlu, iyi çalışmalar.