Wio Terminal and LoRaWAN Chassis Getting Started

I have just received my Wio Terminal LoRaWAN chassis and have some questions as there does not seem to be much information regarding this Wio Terminal addon. I wish to use my chassis in Australia with the TTN but having difficulties in setting the AU915 frequency band. Also I cannot seem to be able to communicate to the E5 module with the AT command set via a serial connection. I always get a KO response which I have interpreted to mean “Error” instead of “OK”. How can I access the AT command set? I can set some frequency bands (EU,US,IN and AS923) so I know my terminal setup is OK.

A further comment on the connection between the two units is the pins on the Wio terminal chassis seem very short and I have some doubts that they make proper contact within the Wio terminal socket when the chassis case is installed…(Probably fixed this by removing the little rubber feet that cover the screws on the back of the Wio which allow the two units to sit closer together.)

Update:After updating the firmware from here https://github.com/disk91/WioLoRaWANFieldTester/blob/master/binaries/WioLoRaWANFieldTester_LoRaE5.uf2 I am able to enter TTN DevEUI, AppKey and NetworkKey etc via the serial connection with D=XXXXXetc and A=XXXetc and K=XXXetc but not convinced I have the AU915 band frequencies set correctly.