curl --request GET \
  --url https://api.zippendo.com/orgs/{orgId}/billing/usage \
  --header 'Authorization: Bearer <token>'

{
  "currentPeriod": {
    "start": "<string>",
    "end": "<string>"
  },
  "shipments": {
    "used": 123,
    "included": 123,
    "overage": 123,
    "overageCharges": 123
  },
  "limits": {
    "teamMembers": {
      "used": 123,
      "limit": 123
    },
    "carriers": {
      "used": 123,
      "limit": 123
    },
    "orderChannels": {
      "used": 123,
      "limit": 123
    },
    "shippingRules": {
      "used": 123,
      "limit": 123
    },
    "senderAddresses": {
      "used": 123,
      "limit": 123
    },
    "apiTokens": {
      "used": 123,
      "limit": 123
    }
  },
  "addOns": [
    {
      "type": "extra_carrier",
      "quantity": 123,
      "unitPrice": 123,
      "totalPrice": 123
    }
  ]
}