django/tests/admin_docs/namespace_urls.py

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

from . import views

backend_urls = ([
    path('something/', views.XViewClass.as_view(), name='something'),
], 'backend')

urlpatterns = [
    path('admin/doc/', include('django.contrib.admindocs.urls')),
    path('admin/', admin.site.urls),
    path('api/backend/', include(backend_urls, namespace='backend')),
]