I followed the django example exactly. But it doesn't work

**
I followed the django example exactly. But it doesn't work. Web page just show the rocket to me.**

my project name: web

app name: main

web.settings.py
=>

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'main',
]

web.urls.py

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('main/', include('main.urls')),
    path('admin/', admin.site.urls),
]

main.urls.py

from django.urls import path
from . import views


urlpatterns = [
    path('', views.index, name='index'),
]

main.views.py

from django.http import HttpResponse


def index(request):
    return HttpResponse("Hello, world. You're at the polls index.")

I hope web page shows "Hello, world. You're at the polls index." to me.

In your main urls file you have set:

urlpatterns = [
    path('main/', include('main.urls')),
    path('admin/', admin.site.urls),
]

Which actually means, that you need to go for localhost:8000/main for your urls in "main" app. If you want to do it without specifying main in the url in your browser, then change it to:

urlpatterns = [
    path('', include('main.urls')),
    path('admin/', admin.site.urls),
]