website/src/ctfs/urls.py

from django.contrib.sitemaps.views import sitemap
from django.urls import path
from .sitemaps import CategorySitemap, CTFSitemap
from . import views

sitemaps = {
    'categories': CategorySitemap(),
    'challenges': CTFSitemap(),
}

urlpatterns = [
        path('<str:cat_slug>/', views.category, name='category'),
        path('<str:cat_slug>/<str:ctf_slug>', views.ctf, name='ctf'),
        path('sitemap.xml', sitemap, {'sitemaps': sitemaps}, name='django.contrib.sitemaps.views.sitemap'),
]