curl --request GET \
  --url https://api.leanrails.com/v1/invoice_items/{id} \
  --header 'Authorization: Basic <encoded-value>'

{
  "id": "<string>",
  "object": "invoiceitem",
  "amount": 123,
  "currency": "<string>",
  "livemode": true,
  "created": 123,
  "invoice": "<string>",
  "customer": "<string>",
  "description": "<string>"
}