http://anonpay666ie3ah4nl55ssimvacwrdkbbji6h4a4snvry26lnemfaxid.onion/documentation/transaction
It is public. private_key string required abcdefghijklmnopqrstuvwxyz0123 A private key associated with the transaction.
Keep it private - it is both the cancellation credential and the
webhook signing secret, and it is returned exactly once, here. expires integer required 1754006400 When the transaction stops being payable, in Unix seconds.