Django新手无法显示Hello World，仍展示默认安装成功页面

我跟着Django教程搭建第一个网站，前期步骤都正常推进，到配置URL Patterns环节出现异常：使用include()函数配置路由后，本地启动服务器，页面显示的还是Django默认的安装成功主页，而非教程要求的"Hello World"文本。我反复核对代码，确保和教程及Django官方文档的写法完全一致，但问题依旧；也查阅了Stack Overflow上的多个解决方案，仍然无法解决。

相关代码文件 #

/first_project/first_project/urls.py #

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

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

/first_project/first_project/settings.py #

INSTALLED_APPS = [
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    "first_app",
]

/first_project/first_app/urls.py #

from django.urls import path
from . import views

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

/first_project/first_app/views.py #

from django.shortcuts import render
from django.http import HttpResponse

# Create your views here.

def index(request):
    return HttpResponse("Hello World")

已尝试的解决方案 #

Stack Overflow上有建议将项目根目录下urls.py中的path("first_app/", include("first_app.urls"))修改为path("", include('first_app.urls'))，但修改后问题并未解决。

项目结构 #

first_project/
├── first_project/
│   ├── __init__.py
│   ├── asgi.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
├── first_app/
│   ├── __init__.py
│   ├── admin.py
│   ├── apps.py
│   ├── migrations/
│   ├── models.py
│   ├── tests.py
│   ├── urls.py
│   └── views.py
└── manage.py

内容的提问来源于stack exchange，提问作者Jared