curl --request GET \
  --url https://api-m.sandbox.paypal.com/v1/commerce/billing/subscriptions/{external_subscription_id}/alerts \
  --header 'Authorization: Bearer <token>'

{
  "alerts": [
    {
      "id": "7e6a89c9-ab69-4702-98f5-c245aca88080",
      "external_subscription_id": "SUB_1752779018503",
      "metric": {
        "name": "Storage usage",
        "code": "Storage_Metrics_1753985710",
        "type": "METERED",
        "description": "GB of storage used in my application",
        "aggregation_type": "SUM",
        "aggregation_field": "gb",
        "field_filters": [
          {
            "key": "region",
            "values": [
              "us-west1"
            ]
          }
        ],
        "id": "1e421308-7ead-4aef-b527-64dd05569668",
        "created_at": "2025-07-31T18:15:12Z"
      },
      "type": "METRIC_CURRENT_USAGE_UNITS",
      "code": "storage_units_current_cycle",
      "name": "Current Usage Alert specific to a Metric units",
      "previous_value": 0,
      "thresholds": [
        {
          "code": "units_used",
          "value": "500000.0",
          "recurring": false
        }
      ],
      "created_at": "2025-08-01T05:58:57Z"
    },
    {
      "id": "14a42687-1814-4419-a111-76ff5792a786",
      "external_subscription_id": "SUB_1752779018503",
      "metric": {
        "name": "Storage usage amount",
        "code": "Storage_Metrics_1753985710",
        "type": "METERED",
        "description": "GB of storage used in my application",
        "aggregation_type": "SUM",
        "aggregation_field": "gb",
        "field_filters": [
          {
            "key": "region",
            "values": [
              "us-west1"
            ]
          }
        ],
        "id": "1e421308-7ead-4aef-b527-64dd05569668",
        "created_at": "2025-07-31T18:15:12Z"
      },
      "type": "METRIC_CURRENT_USAGE_AMOUNT",
      "code": "storage_amount_current_cycle",
      "name": "Current Monetary Usage Alert specific to a Metric",
      "previous_value": 0,
      "thresholds": [
        {
          "code": "warn",
          "value": "1000.0",
          "recurring": false
        }
      ],
      "created_at": "2025-08-01T05:58:53Z"
    },
    {
      "id": "13aac90e-927a-4203-8d42-11a388b91308",
      "external_subscription_id": "SUB_1752779018503",
      "type": "CURRENT_USAGE_AMOUNT",
      "code": "current_usage_amount_aggregated_current_cycle",
      "name": "Current Cycle Monetary Usage Alert",
      "previous_value": 0,
      "thresholds": [
        {
          "code": "hard",
          "value": "9000.1",
          "recurring": false
        }
      ],
      "last_processed_at": "2025-08-03T10:04:21Z",
      "created_at": "2025-08-01T05:58:48Z"
    },
    {
      "id": "f5ca7539-e540-4d92-a416-fcece5970bf4",
      "external_subscription_id": "SUB_1752779018503",
      "type": "LIFETIME_USAGE_AMOUNT",
      "code": "lifetime_usage_alert",
      "name": "Lifetime Monetary Usage Alert",
      "previous_value": 0,
      "thresholds": [
        {
          "code": "warn",
          "value": "5000.0",
          "recurring": false
        },
        {
          "code": "hard",
          "value": "10000.0",
          "recurring": false
        },
        {
          "code": "hard",
          "value": "2000.0",
          "recurring": true
        }
      ],
      "created_at": "2025-07-31T18:28:31Z"
    }
  ],
  "meta": {
    "total_count": 4,
    "total_pages": 1,
    "current_page": 1
  }
}

{
  "name": "<string>",
  "debug_id": "<string>",
  "message": "<string>",
  "details": [
    {
      "field": "<string>",
      "value": "<string>",
      "location": "<string>",
      "issue": "<string>",
      "description": "<string>"
    }
  ]
}

{
  "name": "UNPROCESSABLE_ENTITY",
  "message": "The requested action could not be performed, semantically incorrect, or failed business validation.",
  "debug_id": "90957fca61718",
  "details": [
    {
      "field": "/email",
      "value": "sdfwdj@sdfs.com",
      "location": "body",
      "issue": "UNSUPPORTED_EMAIL",
      "description": "The email provided is not supported."
    }
  ]
}

{
  "name": "INTERNAL_SERVER_ERROR",
  "message": "An internal server error has occurred.",
  "debug_id": "90957fca61718"
}