

Sorry for the delay in checking your reply.
What I mean by SDK tools are three programs in the tools folder in the SDK zip file. (flashtool, testsuitetool, vcomtool)
At first, in vcomtool, both the dongle and adk board were visible in the device list, but when I selected them, the problem appeared as shown in the screenshot. Instead, the adk board worked as described in the text (the ADK board begins to be recognized by the VCOM Tool after flashing the firmware.... ) and then sent a response to 'sending headset_get_version command' from vcomtool. (3.1.2003.C1.NgVC.KgHC)
However, the dongle still did not work even though I connected the USB. (Error in screenshot) I would like to solve this problem using flashtool, but I cannot connect to flashtool. Currently, it seems that the dongle and board are not paired. There is still no audio.
The flashtool cannot be connected to both the ADK board and the dongle, but there is a way to flash the ADK Board using MCUXpresso using the J-Link Debugger. However, the conclusion is that there is no way to flash the dongle.
This is my current status.