ACP Workbench with Up2stream mini clone

I bought unfortunately a clone of Up2stream mini, WB05, with the project name Huan_SoundSystem. I would like to get advantage of gpio configured to turn off an amplifier, when audio is turned off.
I encountered two problems:

  1. When I connect the board with micro USB, it is not detected as USB Audio. I thought that maybe after OTA upgrade it will work, but not. I checked the physical connection, and I can confirm that USB socket is connected to D+ and D- of LinkyPlay A31.
  2. GPIO pins cannot be accessed directly from the SoundSystem board. I guess I can make physical connection to the LinkyPlay instead, however I don’t know which GPIOs are corresponding to the listed in ACP Workbench (LinkyPlay exposes 5 GPIOs).

Do you have any idea if it is possible to enable USB connection and communicate with ACP Workbench?

Best regards,