Not clear situation with Django URL?

Question

Django

The bottom line is that he sees links not as links, but as files. This is most likely related to settings.py, but I myself do not understand what to do. Can't even see the admin.

CODE:
settings.py

'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR, "mainapp/templates")],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'mysite.wsgi.application'


# Database
# https://docs.djangoproject.com/en/3.0/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    }
}


# Password validation
# https://docs.djangoproject.com/en/3.0/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/3.0/topics/i18n/

LANGUAGE_CODE = 'ru'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.0/howto/static-files/

STATIC_URL = '/static/'
STATIC_DIR = os.path.join(BASE_DIR, 'static')
STATICFILES_DIRS = [STATIC_DIR]
MEDIA_ROOT = os.path.join(BASE_DIR, 'templates')

application url

from django.urls import path
from .views import *

urlpatterns = [
  path('', get),
  path('genres/<int:genres_id>/', get_genre),
  path('register/', register)
]

root url

from django.conf import settings
from django.conf.urls.static import static
from django.contrib import admin
from django.urls import path, include
from django.conf import settings

urlpatterns = [
    path('', include('mainapp.urls')),
    path('register/', include('mainapp.urls')),
    path('admin/', admin.site.urls),

]


if settings.DEBUG:
  urlpatterns += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

views.py

def get_genre(request, genres_id):
  anime = Anime.objects.filter(genres_id=genres_id)
  genre = Genre.objects.get(pk=genres_id)
  return render(request, 'mainapp/genres.html', {'anime': anime, 'genre': genre})

def register(request):
  return render(request, 'mainapp/register.html', {})