Azure Data Factory managed private endpoint to Azure PostgresSQL flexible server

Question

In my infra I have a Vnet with two subnets:

• application-subnet
• delegated-subnet

The Azure Data Factory instance is on application-subnet.

The Azure PostgreSQL flexible server is in delegated-subnet and is configured with Private Access (VNET Integration).
Pricing tier: General Purpose

Compute size: Standard_D2s_v3 (2 vCores, 8 GiB memory, 3200 max iops)

Storage: 32 GiB

In the ADF instance I am trying to create a linked service to the db using Azure managed integration runtime. In the ADF private endpoint form, I choose the subscription but the dropdown with database server name is not filled:

I tried to create it from terrafom script:

resource "azurerm_data_factory_managed_private_endpoint" "db-mpe" {
  data_factory_id    = azurerm_data_factory.adf.id  
  target_resource_id = data.azurerm_postgresql_flexible_server.postgres_db_server.id  
  subresource_name   = "postgresqlServer"
}

But then it is pending for approval and there is no section in PostgreSQL db to approve it.
What should I do?

I also tried to create a private endpoint:

resource "azurerm_private_endpoint" "db_private_endpoint" {  
  name                = "${local.instance_name}-pe"  
  resource_group_name = data.azurerm_resource_group.common_rg.name  
  location            = data.azurerm_resource_group.common_rg.location
  
  subnet_id = data.azurerm_subnet.connectivity_postgres_delegated_subnet.id
         
  private_service_connection {    
    name                           = "${local.instance_name}-sc"    
    is_manual_connection           = "false"    
    private_connection_resource_id = module.postgres.db.id    
    subresource_names              = ["postgresqlServer"]  
  }
}

Error: creating Private Endpoint (Subscription: "xxxx"

78│ Private Endpoint Name: "xxx-pe"): performing CreateOrUpdate: unexpected status 400 with error: SubscriptionNotRegisteredForFeature: Subscription /subscriptions/xxx/resourceGroups//providers/Microsoft.Network/subscriptions/ is not registered for feature Microsoft.Network/AllowPrivateEndpoints required to carry out the requested operation.

What can I do?