terraform v12.x count and for_each are using together

main.tf

data "azurerm_client_config" "current" {}

resource "azurerm_key_vault" "keyvault" {
  count = "${length(var.vaultnames)}"
  name                = "${var.servicename}-${var.vaultnames[count.index]}"
  location            = "${var.keyvault_location}"
  resource_group_name = "${var.keyvault_resource_group}"
  tenant_id           = "${data.azurerm_client_config.current.tenant_id}"

  sku_name = "standard"

  dynamic "access_policy" {
    for_each = var.object_user_id
    
    content {
      tenant_id = "${data.azurerm_client_config.current.tenant_id}"
      object_id = access_policy.value
      secret_permissions = [
        "get",
        "list",
      ]
    }
    

  }

  tags = {
    environment = "${var.tag_environment}"
  }
}

variables.tf

variable "servicename" {}

variable "vaultnames" {
    type=list(any)
    default = ["test", "users"]
}

variable "keyvault_location" {}
variable "keyvault_resource_group" {}
variable "tag_environment" {}
variable "object_id" {
    default = {
        "xyz" = "3704c477-d527-4074-82c4-7f40be0435bfb"
    }
}

variable "object_user_id" {
    default = {
        "abc" = "3704c477-d527-4074-82c4-7f40be0435bfa"
        "efg" = "3704c477-d527-4074-82c4-7f40be0435bfb"
        "hjk" = "3704c477-d527-4074-82c4-7f40be0435bfc"
    }    
}