does anybody know how to contol the CNC shield

I have this one

I know how to move the X, Y, Z motors

But there is also A step motor, 4th.

Does anybody have code how to get it moving ?

From the Kuman site.

CNC Shield Board:
● Latest Arduino CNC Shield Version 3.0
● GRBL 0.9 compatible
● 4-Axis support (X, Y, Z , A-Can duplicate X,Y,Z or do a full 4th axis with custom firmware using pins D12 and D13)
● 2 x End stops for each axis (6 in total)
● Coolant enable
● Compatible with A4988 or DRV8825 stepper driver
● Runs on 12-36V DC

I would put a link to the Kuman site but it is not secure.

Google "Kuman cnc sheild" and you should see their site. Does the board look like yours?

To use the A axis, jumper across the indicated blue header pins and the indicated yellow pins. Then send the steps for A axis out pin 12 and set the direction with pin 13. Note that when you do that you lose ability to control the spindle enable and direction.

clone A axis.jpg