How can I make the Graphical block software available for the Micro:bit Driver Expansion Board?

I download the software from: https://github.com/DFRobot/pxt-motor
But there is no information on how to use this software.

So I tried something:
I installed pxt with: npm install -g pxt
Next: pxt build

Error message:
Cannot find node_modules/pxtcli.json nor pxtarget.json
Couldn't find PXT; maybe try 'pxt target microbit'?

What did I do wrong?
Hi, all
Please need help.
I have this board (MicroBit Drive expansion board V2)...I downloaded the extension DFRobot pxt motor. I try to install but I'm not sure which file I should select. it is installed (DF-motor) by selecting MAIN, but it gives me an error when not finding the name of the M1 motor, etc.
please see images.

thanks in advance
cant find name motor.JPG