File "c:\work\memo\memo\on\urls.py", line 12, in <module>
    path('', include(router.urls)),
  File "C:\Users\i.kovalenko\Envs\memo\lib\site-packages\rest_framework\routers.py", line 98, in urls
    self._urls = self.get_urls()
  File "C:\Users\i.kovalenko\Envs\memo\lib\site-packages\rest_framework\routers.py", line 359, in get_urls
    urls = super().get_urls()
  File "C:\Users\i.kovalenko\Envs\memo\lib\site-packages\rest_framework\routers.py", line 257, in get_urls
    routes = self.get_routes(viewset)
  File "C:\Users\i.kovalenko\Envs\memo\lib\site-packages\rest_framework\routers.py", line 173, in get_routes
    extra_actions = viewset.get_extra_actions()
AttributeError: 'function' object has no attribute 'get_extra_actions'

from rest_framework.decorators import api_view
from rest_framework.response import Response

@api_view()
def ongraph(request):
    return Response({"message": "Hello, world!"})