configured urls so that views is visible

joeiyucoco_reading/bookshelf/urls.py

-from django.shortcuts import render
+from django.urls import path
+from .views import index
 
-# Create your views here.
+urlpatterns = [
+    path('', index, name='index'),
+]
+# This might be needed, depending on your Django version
+app_name = "bookshelf"

joeiyucoco_reading/bookshelf/views.py

 from django.shortcuts import render
+from django.http import HttpResponse
 
+def index(request):
+    return HttpResponse('Hello World!')
 # Create your views here.

joeiyucoco_reading/joeiyucoco_reading/settings.py

@@ -40,6 +40,7 @@ INSTALLED_APPS = [
     'django.contrib.sessions',
     'django.contrib.messages',
     'django.contrib.staticfiles',
+    'bookshelf',
 ]
 
 MIDDLEWARE = [

joeiyucoco_reading/joeiyucoco_reading/urls.py

@@ -14,8 +14,9 @@ Including another URLconf
     2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
 """
 from django.contrib import admin
-from django.urls import path
+from django.urls import include, path
 
 urlpatterns = [
+    path('bookshelf/', include('bookshelf.urls', namespace="bookshelf")),
     path('admin/', admin.site.urls),
 ]