curl --request GET \
  --url https://api.halth.com/v1/organisations/{organisationId}/billable-items

{
  "items": [
    {
      "name": "<string>",
      "basePrice": 123,
      "totalPrice": 123,
      "taxAmount": 123,
      "taxRate": 123,
      "id": "<string>",
      "itemCode": "<string>",
      "serviceItem": {
        "id": "<string>",
        "itemCode": "<string>",
        "category": "<string>",
        "description": "<string>"
      },
      "pmsBillableItemId": "<string>"
    }
  ],
  "page": 1,
  "limit": 10,
  "totalItems": 100,
  "totalPages": 10
}