Get invoice

{
  "type": "object",
  "description": "> View the coverage for invoices in the <a className=\"external\" href=\"https://knowledge.codat.io/supported-features/accounting?view=tab-by-data-type&dataType=invoices\" target=\"_blank\">Data coverage explorer</a>.\n\n## Overview\n\nAn invoice is an itemized record of goods sold or services provided to a [customer](https://docs.codat.io/accounting-api#/schemas/Customer).\n\nIn Codat, an invoice contains details of:\n\n- The timeline of the invoice—when it was raised, marked as paid, last edited, and so on.\n- How much the invoice is for, what portion of the invoice is tax or discounts, and what currency the amounts are represented in. \n- Who the invoice has been raised to; the _customer_.\n- The breakdown of what the invoice is for; the _line items_.\n- Any [payments](https://docs.codat.io/accounting-api#/schemas/Payment) assigned to the invoice; the _payment allocations_.\n\n> **Invoices or bills?**  \n>\n> In Codat, invoices represent accounts receivable only. For accounts payable invoices, see [Bills](https://docs.codat.io/accounting-api#/schemas/Bill).\n\n> **Invoice PDF downloads**  \n>\n> You can <a className=\"external\" href=\"https://docs.codat.io/accounting-api#/operations/get-invoice-pdf\" target=\"_blank\">download a PDF version</a> of an invoice for supported integrations.\n> \n> The filename will be invoice-{number}.pdf.\n\n> **Referencing an invoice in Sage 50 and ClearBooks**\n>\n> In Sage 50 and ClearBooks, you may prefer to use the **invoiceNumber** to identify an invoice rather than the invoice **id**. Each time a draft invoice is submitted or printed, the draft **id** becomes void and a submitted invoice with a new **id** exists in its place. In both platforms, the **invoiceNumber** should remain the same.",
  "required": [
    "amountDue",
    "issueDate",
    "status",
    "totalAmount",
    "totalTaxAmount"
  ]
}