memo Optional field. User provided data encrypted to the memo key of the "to" account.[ 14,{ "fee": { "amount": 0, "asset_id": "1.3.0" }, "issuer": "1.2.0", "asset_to_issue": { "amount": 0, "asset_id": "1.3.0" }, "issue_to_account": "1.2.0", "extensions": [] } ]