No post found matching the query, what is my mistake?

Question

Django

Hello, I am creating a small blog. I use CBV. When switching to pk(127.0.0.1:8000/detail/1/), the error No post found matching the query occurs, although there are posts in the database. What's my mistake?
models.py

class Post(models.Model):
    theme = models.CharField(max_length=100)
    post_text = models.CharField(max_length=4000)
    pub_date = models.DateTimeField('date published')

    def get_absolute_url(self):
        return reverse("Blog:index", kwargs={'pk': self.pk})  # реверс - работает без пк kwargs={'pk': self.pk}

    def __str__(self):
        return self.theme

    def was_published_recently(self):
        now = timezone.now()
        return now - datetime.timedelta(days=1) <= self.pub_date <= now
    was_published_recently.admin_order_field = 'pub_date'
    was_published_recently.boolean = True
    was_published_recently.self_description = 'Published recently?'

urls.py

app_name = 'Blog'
urlpatterns = [
    path('detail/', views.IndexView.as_view(), name='index'),
    path('create/', views.CreateView.as_view(), name='create'),
    path('detail/<int:pk>/', views.DetailView.as_view(), name='detail'),
]

views.py

class IndexView(generic.ListView):
    queryset = Post.objects.all()
    template_name = 'Blog/index.html'
    context_object_name = 'latest_post_list'

class DetailView(generic.DetailView):
    template_name = "Blog/detail_post.html"
    #context_object_name = 'Post'
    queryset = Post.objects.all()

class CreateView(generic.CreateView):
    model = Post
    template_name = 'create_post.html'
    fields = ['theme',
              'post_text',
              'pub_date']

Answer 1

class DetailView(generic.DetailView):
    template_name = "Blog/detail_post.html"
    model = Post

queryset is not needed as it works with one object
https://ccbv.co.uk/projects/Django/2.2/django.view...

Answer 2

Define the get_object method

from django.shortcuts import get_object_or_404


class DetailView(generic.DetailView):
    object = Post 
    template_name = "Blog/detail_post.html"
    
    def get_object(self, queryset=None):
        return get_object_or_404(Post, pk=self.kwargs.get('pk'))