# Use Invoice4U with checkout API

You can generate Invoice4U receipts through [Checkout](/api-reference/open-api-references/checkout.md) API.

The table below presents the Invoice4U specific fields (required and not required) for checkout API:

| Parameters          | Type                                                 | Description                                                        |
| ------------------- | ---------------------------------------------------- | ------------------------------------------------------------------ |
| `receipt_type`      | Required (string)                                    | Supported types: “INVOICE\_RECEIPT”, “FULL\_RECEIPT” & “INVOICE”   |
| `line_items`        | Required (object) (for INVOICE and INVOICE\_RECEIPT) | Object carrying the parameters required for the product line items |
| `name`              | <p>Required (string) </p><p> </p>                    | Descriptive name of the order line item                            |
| `quantity`          | Required (integer)                                   | Quantity of the order line item                                    |
| `unit_price`        | Required (integer)                                   | Single unit price (tax included)                                   |
| `tax_rate`          | Optional (number)                                    | Tax rate (0 or 17)                                                 |
| `total_amount`      | Requited (integer)                                   | Total product amount (quantity × unit\_price)                      |
| `sku`               | Optional (string)                                    | The stock keeping unit (SKU) for the item                          |
| `sales_description` | Optional (string)                                    | General description of the document                                |

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