Raspbee ii / ZHA / deCONZ - serial path?

I embarked on getting zigbee support by buying a Raspbee ii. I hit a snag and finally got far enough to change my confit.txt on the raspberry Pi and get to THIS point, but now I am stuck. I’ve googled, I’ve prayed, I’ve poked around in the Pi but I’m stuck.

Can someone point me in the direction of figuring out the serial path for the raspbee ii needed as part of the setup?