如何在使用copyIndex时将ResourceId作为VM的输出

"resources": [
  {
    "type": "Microsoft.Compute/virtualMachines",
    "name": "[concat('vm', copyIndex())]",
    "apiVersion": "2021-03-01",
    "location": "[resourceGroup().location]",
    "properties": {
      "hardwareProfile": {
        "vmSize": "Standard_DS2_v2"
      },
      "storageProfile": {
        "imageReference": {
          "publisher": "MicrosoftWindowsServer",
          "offer": "WindowsServer",
          "sku": "2019-Datacenter",
          "version": "latest"
        },
        "osDisk": {
          "createOption": "FromImage"
        }
      },
      "networkProfile": {
        "networkInterfaces": [
          {
            "id": "[resourceId('Microsoft.Network/networkInterfaces', concat('nic', copyIndex()))]"
          }
        ]
      }
    },
    "outputs": {
      "vmResourceId": {
        "type": "string",
        "value": "[resourceId('Microsoft.Compute/virtualMachines', concat('vm', copyIndex()))]"
      }
    }
  }
]