curl --request POST \
  --url https://api.meetcampfire.com/coa/api/v1/invoice/{invoice_id}/default-payment \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "posted_at": "2023-12-25",
  "transaction_amount": 0
}
'

{
  "default_payment_amount": 0,
  "payment_term_discount_note": "<string>"
}