terraform created Kubenet AKS doesn't link routetable to app gateway subnet?

As per this kubenet: associate route table to appgw subnet

when you create AGIC to a app gateway, it should automatically link the routetable on AKS subnet to app gateway subnet, this is required because we are using kubenet.

however, when I'm creating cluster with terraform, I'm not seeing that. my terraform version is

Terraform v1.0.4 on windows_amd64

• provider registry.terraform.io/hashicorp/azurerm v2.94.0

addon_profile {
    http_application_routing {
      enabled = var.http_application_routing_enabled
    }

    azure_policy {
      enabled = var.azure_policy_enabled
    }

    oms_agent {
      enabled                    = var.monitoring_insights_enabled
      log_analytics_workspace_id = var.log_analytics_workspace_id
    }

    ingress_application_gateway {
      enabled      = var.ingress_application_gateway_enabled
      subnet_id    = var.ingress_agic_subnet == null ? null : data.azurerm_subnet.ingress_agic_subnet[0].id
      gateway_name = var.ingress_application_gateway_name
      gateway_id   = var.ingress_application_gateway_id

    }
  }