Django no reverse match for Blog Posts models

#urls.py
---------------
sitemaps = {
    'static': StaticViewSitemap,
    'blog': BlogSitemap,
}
urlpatterns = [
    path('admin/', admin.site.urls),
    path('i18n/', include('django.conf.urls.i18n')),
    path('sitemap.xml', sitemap, {'sitemaps': sitemaps},name='django.contrib.sitemaps.views.sitemap'),
]
-----------------
#models.py
-----------------
blablabla typical Posts model with:

def get_absolute_url(self):
        return reverse('blog:post', kwargs={'slug':self.slug})
------------------
#sitemaps
-----------------

class StaticViewSitemap(Sitemap):
    priority = 0.5
    changefreq = 'daily'
    protocol = "https"

    def items(self):
        return ['main:contact-us', 'main:homepage','blog:blog']

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


class BlogSitemap(Sitemap):
    changfreq = "daily"
    priority = 1.0

    def items(self):
        return Post.objects.filter(status='p')

    def lastmod(self, obj):
        return obj.published