Terraform-GCP cloud functions: how to attach log based metrics to google alert policy

Question

I need to create google alert policy when the cloud function fails using terraform. I am trying to do:

1. creating email channel
2. craete log based metrics
3. create alert policy related to setp

Here is my code:

# Create a Notification Channel
resource "google_monitoring_notification_channel" "email_channel_1" {
  display_name = "Email_Channel"
  type         = "email"

  labels = {
    email_address = "[email protected]"  
  }
}

# Create log based metrics
resource "google_logging_metric" "cf_log_based_metrics" {
    name        = "${var.ENVIRONMENT}_cf_log_metrics"
    description = "CF error metrics"
    filter     = "resource.type=\"cloud_function\" resource.labels.function_name=\"${google_cloudfunctions_function.mycf.name}\" severity=ERROR OR severity=CRITICAL"
  
    metric_descriptor {
        metric_kind = "DELTA"
        value_type  = "INT64"
        unit        = "1"
    }
    
}

# Create an Alert Policy
resource "google_monitoring_alert_policy" "cf_alert_policy" {
    display_name = "${var.ENVIRONMENT}_cf_alert_policy"
    combiner     = "OR"
    conditions {
        display_name = "CF_error_notification"
        condition_threshold {
            filter     = "metric.type=\"logging.googleapis.com/user/${google_logging_metric.cf_log_based_metrics.name}\""
            duration        = "60s"            
            comparison      = "COMPARISON_GT"
            threshold_value = 0.0
            aggregations {
                    alignment_period    = "60s"
                    per_series_aligner  = "ALIGN_RATE"
            }
        }
    }

    notification_channels = [google_monitoring_notification_channel.email_channel_1.name]

}

I am getting the issue:

│ Error: Error creating AlertPolicy: googleapi: Error 400: Field alert_policy.conditions[0].condition_threshold.filter had an invalid value of "metric.type="logging.googleapis.com/user/dev_cf_log_metrics"": must specify a restriction on "resource.type" in the filter; see "https://cloud.google.com/monitoring/api/resources" for a list of available resource types.
│ 
│   with google_monitoring_alert_policy.cf_alert_policy,
│   on main.tf line 538, in resource "google_monitoring_alert_policy" "cf_alert_policy":
│  538: resource "google_monitoring_alert_policy" "cf_alert_policy" {

Let me know where it went wrong.