curl --request GET \
  --url https://api.railmail.app/api/v1/billing/invoices \
  --header 'X-API-Key: <api-key>'

{
  "data": [
    {
      "id": 123,
      "externalId": "<string>",
      "status": "<string>",
      "amountCents": 123,
      "currency": "<string>",
      "invoiceUrl": "<string>",
      "invoiceNumber": "<string>",
      "billingReason": "<string>",
      "paidAt": "2023-11-07T05:31:56Z",
      "createdAt": "2023-11-07T05:31:56Z"
    }
  ],
  "pagination": {
    "page": 123,
    "size": 123,
    "totalElements": 123,
    "totalPages": 123,
    "hasNext": true,
    "hasPrevious": true
  }
}