I Guess you get what you pay for.
Buy cheap Chinese boards, except cheap spaghetti code or no instructions to avoid bricking.
To answer your question, the board is in bootloader mode. Seen this on other devices like arcade controller PCBs or USB adapters that are in bootloader mode. Usually you unplug and replug the device either before or after running the flash update tool, but getting codes to make the flasher execute may be hard with a bricked board (I guess use another keyboard). If that doesn't fix it, contact the Chinese company you bought it from, see if you can ask for help, or an RMA, otherwise, toss the keyboard.