Django NoReverseMatch at /sitemap.xml error for static views

I followed the instruction on django documentation, but I am getting this error when trying to create the sitemap.xml for my app. (also the similar questions on stackoverflow were not describing my case)

The html pages that I would like to add to the sitemap are not based on any models, but they have some forms in their footers. (That's why the urls don't contain "as_view()". I have also added

INSTALLED_APPS = [
    ...
    'django.contrib.sites',
    'django.contrib.sitemaps',
    '''
]

to settings.py file.

Here are more details:

App --> main

main/urls.py

from django.urls import path
from . import views

app_name = 'main'

urlpatterns = [
    path('', views.HomeView, name='homepage'),
    path('about/', views.AboutView, name='about'),
    path('contact/', views.Contact, name='contact'),
]

main/sitemap.py

from django.contrib.sitemaps import Sitemap
from django.urls import reverse

class StaticViewSitemap(Sitemap):
    changefreq = 'daily'
    priority = 0.9

    def items(self):
        return ['homepage','about','contact']

    def location(self, item):
        return reverse(item)

Project --> dcohort

dcohort/urls.py

from argparse import Namespace
from django.contrib import admin
from django.urls import path, include
from django.contrib.sitemaps.views import sitemap
from main.sitemaps import StaticViewSitemap
from django.conf import settings
from django.conf.urls.static import static

sitemaps = {
    'staticviews': StaticViewSitemap,
}

urlpatterns = [
    path('', include('main.urls', namespace='main')),
    path('sitemap.xml', sitemap, {'sitemaps': sitemaps},
        name='django.contrib.sitemaps.views.sitemap'),
]

I finally figured the problem. I should have appended the app name to the page url name.

The main/sitemap.py would be:

from django.contrib.sitemaps import Sitemap

from django.urls import reverse

class StaticViewSitemap(Sitemap):
    changefreq = 'daily'
    priority = 0.9

    def items(self):
        return ['main:homepage','main:about','main:contact']

    def location(self, item):
        return reverse(item)