Updates an invoice's fields or line items. Send only the fields you want to change, inside an invoice object; the accepted fields are the same as when creating one.

• To change a line item, include its id in invoice_line_items_attributes. To remove one, include its id with _destroy: true. Items without an id are added.
• Totals are recalculated on every save.
• Changing amount_paid is only accepted from a role with the Manage invoices & payments permission. The change is recorded as a single manual payment adjustment so the invoice's payment history stays consistent; it is ignored for other roles.
• Setting status to sent or paid can tick off matching items on the job's stage checklist. If the company has connected QuickBooks, a sent invoice is synced there.
• The token's role must be able to view all company records, or the token's user must have created the invoice. The token needs the write scope.