Update Invoice
Updates an existing invoice in Quaderno by modifying allowed fields. This action sends a PUT request to /invoices/{id} and returns the complete updated invoice. Only specific fields can be modified after invoice creation: purchase order number (po_number), tags (tag_list), payment details (payment_details), notes, billing address (street_line_1, street_line_2), custom metadata, and file attachments. Use this when you need to add or modify administrative information on an invoice that hasn't been finalized or paid. Fields not specified in the request remain unchanged.