I have a Django project with the following urlpattern defined on project level:

urlpatterns = [
    path('', include(('ws_shopify.urls', 'ws_shopify'), namespace='shopify')),
]

The file ws_shopify.urls defines the following urlpatterns:

urlpatterns = [
    path('api/shopify/', ShopifyWebhookAPIView.as_view(), name='webhook'),
]

The class ShopifyWebhookAPIView defines the following endpoint:

from rest_framework.views import APIView

class ShopifyWebhookAPIView(APIView):
    @action(detail=False, methods=['post'], url_path='(?P<webshop_name>.+)/order_created', name='order-created')
    def order_created(self, request: Request, webshop_name=None):
        return Response({'message': f'Order created for {webshop_name}'})

My question is:
What is the correct name of this endpoint to be used in a test case using reverse()?

I am trying this now:

class WebhookTestCase(TestCase):
    def test_that_url_resolves(self):
        url = reverse('shopify:webhook:order-created', kwargs={'webshop_name': 'my-shop'})
        self.assertEqual(url, '/api/shopify/my-shop/order_created')

But this fails with the following error message:

django.urls.exceptions.NoReverseMatch: 'webhook' is not a registered namespace inside 'shopify'