Bed leveling problem

I've tried using the SD card that came with the Creator Pro to perform the bed leveling process. However, it positions the extruders at approx the center of the bed and then instructs me to press "M" to continue. What is this? I'm not connected to the computer [which uses Simplfy3D], so I would think this operation should be a self contained procedure. What am I doing wrong?

My PC is a room too far from the printer to use a usb cable. So I also use the SD card. instead of "M" I simply hit OK, and move the extruders manually. Then rehome the axis.