curl --request GET \
  --url https://api.metronome.com/v1/billable-metrics/{billable_metric_id} \
  --header 'Authorization: Bearer <token>'

{
  "data": {
    "id": "8deed800-1b7a-495d-a207-6c52bac54dc9",
    "name": "CPU Hours",
    "event_type_filter": {
      "in_values": [
        "cpu_usage"
      ]
    },
    "property_filters": [
      {
        "name": "cpu_hours",
        "exists": true
      },
      {
        "name": "region",
        "exists": true,
        "in_values": [
          "EU",
          "NA"
        ]
      },
      {
        "name": "machine_type",
        "exists": true,
        "in_values": [
          "slow",
          "fast"
        ]
      }
    ],
    "aggregation_type": "SUM",
    "aggregation_key": "cpu_hours",
    "group_keys": [
      [
        "region"
      ],
      [
        "machine_type"
      ]
    ]
  }
}