transfer_destination object fields:
address — string; standard or integrated address of a recipient.
amount — unsigned int; amount of coins to be sent;
Integrated address usage
If you use multiple addresses in destinations field, make sure there are maximum 1 integrated address involved, or, if "payment id" parameter was specified, then integrated addresses are not allowed.
tx_hash — string; hash identifier of the transaction that was successfully sent.
tx_unsigned_hex — string; hex-encoded unsigned transaction (for watch-only wallets; to be used in cold-signing process).