Unlike KingSmith R1 PRO treadmill, this device uses caesar cipher for ecryption BLE packet. Reversing code couldn't be not perfect. (a cipher table has missing part. and every devices could have different table.)
the original code is https://github.com/custom-components/ble_monitor/blob/master/custom_components/ble_monitor/ble_parser/get_beacon_key.py but, almost changed.