Update tutorial-django-app-service-postgres.md

Author: mksuni

articles/postgresql/flexible-server/tutorial-django-app-service-postgres.md

@@ -107,11 +107,12 @@ Create an App Service app (the host process) with the [az webapp up](/cli/azure/
 
 az webapp up --resource-group myresourcegroup --location westus2 --plan DjangoPostgres-tutorial-plan --sku S1 --name <app-name>
 
-# Enable VNET integration for web app.
+# Create subnet for web app
+az network vnet subnet create --name <webapp-subnet-name> --resource-group myresourcegroup --vnet-name <vnet-name>
 
 # Replace <vnet-name> and <subnet-name> with the virtual network and subnet name that the Azure Database for PostgreSQL flexible server instance is using.
 
-az webapp vnet-integration add -g myresourcegroup -n  mywebapp --vnet <vnet-name> --subnet <subnet-name>
+az webapp vnet-integration add -g myresourcegroup -n  mywebapp --vnet <vnet-name> --subnet <weabpp-subnet-name>
 
 # Configure database information as environment variables