Micro USB cable

This is a regular USB-A to Micro USB cable useful for APU6 motherboards. There's nothing special about this cable - you probably already have a similar one you can use.

APU6 motherboards have the USB to DB9F serial adapter chip built-in, so the external converter is not needed. 

If you are using macOS install drivers as described here MacOS/Windows drivers for serial-USB adapter

If you are using Windows, follow these instructions Windows Serial connection