Setting an alert on a resource group in Azure

hey there

am struggling with a problem with Terraform. any help is appreciated!

what i want to do is set an alert on a number of VMs in a resource group in Azure. I can do this via the portal

my code is:

resource “azurerm_monitor_metric_alert” “devcpualert”{

name = “Dev Environments - CPU alert”

resource_group_name = azurerm_resource_group.rg.name

scopes = ["/subscriptions/ea7bc135-xxxx-xxxx-xxxx-3a104eb84a98/resourceGroups/RG1", “/subscriptions/ea7bc135-xxxx-xxxx-xxxx-3a104eb84a98/resourceGroups/RG2”]

description = “”

enabled = true

severity = 3

tags = {}

target_resource_type = Microsoft.Compute/virtualMachines

criteria {

    metric_namespace      = "microsoft.compute/virtualmachines"

    metric_name           = "Percentage CPU"

    aggregation           = "Average"

    operator             = "GreaterThan"

    threshold            = 99.0

    

  }

action {

action_group_id= "/subscriptions/ea7bc135-bf0a-470c-a0c4-3a104eb84a98/resourceGroups/RGxxxx/providers/microsoft.insights/actionGroups/123devops"

}

}

can run Terraform plan ok - its only when i run Terraform apply i get this:

Error: Error creating or updating metric alert “Dev Environments - CPU alert” (resource group “xxxx”): insights.MetricAlertsCertsClient#CreateOrUpdate: Failure responding to request: StatusCode=400 – Original Error: autorest/azure: Service returned an error. Status=400 Code=“BadRequest” Message="Alerts are currently not supported at resource group level for . Activity ID

how can i do this with Terraform.
I need to be able to do this using RG not subscriptions etc.

Thanks a mil.

Neil.