{
  "event": {
    "external_subscription_id": "string",
    "transaction_id": "unique_transaction_identifier",
    "code": "billable_metric_code",
    // Event Unix Timestamp
    "timestamp": 1620000000,
    "properties": {
      // Should respect the format of your billable metric
      "my_property": "my_value"
    },
    // Optional, used for the dynamic pricing feature, defaulted to 0
    "precise_total_amount_cents": 1000
  }
}