Google Cloud Platform API Gateway in Terraform

apikeys.tf

/*
// If you get this error, ensure that your $GOOGLE_APPLICATION_DEFAULTS env
variable is set to a Service Account. Regular cloud identities are not
allowed to hit apikeys.googleapis.com because in the eyes of Google, API keys
are insecure compared to OAuth2 tokens.

│ Error: Error creating Key: failed to create a diff: failed to retrieve Key
| resource: googleapi: Error 403: Your application has authenticated using
| end user credentials from the Google Cloud SDK or Google Cloud Shell which
| are not supported by the apikeys.googleapis.com. We recommend configuring
| the billing/quota_project setting in gcloud or using a service account
| through the auth/impersonate_service_account setting. For more information
| about service accounts and how to use them in your application, see
| https://cloud.google.com/docs/authentication/. If you are getting this error
| with curl or similar tools, you may need to specify 'X-Goog-User-Project' HTTP
| header for quota and billing purposes. For more information regarding
| 'X-Goog-User-Project' header, please check https://cloud.google.com/apis/docs/system-parameters.
│ Details:
│ [
│   {
│     "@type": "type.googleapis.com/google.rpc.ErrorInfo",
│     "domain": "googleapis.com",
│     "metadata": {
│       "consumer": "projects/0123456789",
│       "service": "apikeys.googleapis.com"
│     },
│     "reason": "SERVICE_DISABLED"
│   }
│ ]
│ 
│   with google_apikeys_key.api_key,
│   on main.tf line 165, in resource "google_apikeys_key" "api_key":
│  165: resource "google_apikeys_key" "api_key" {
│ 
╵
*/
resource "google_apikeys_key" "api_key" {
  name         = "api-key-name"
  display_name = "api-key-display-name"
  project      = var.project_id

  restrictions {
    # Restrict to specific Google API service
    api_targets {
      service = google_api_gateway_api.api.managed_service 
      methods = ["GET*"]
    }
    # Set referrer URL
    browser_key_restrictions {
      allowed_referrers = ["goatherding.club"]
    }
  }
}