The Motor FeatherWing includes screw block terminals for connecting stepper motor and the 12v battery pack. The project uses a single stepper motor.
Solder Screw Block Terminals
Insert two 2-pin screw block terminals into the M3 and M4 motor pins. Then insert one 2-pin screw block terminal into the power port. Solder the pins in place. You can optionally use M1 and M2 ports, just remember to reflect that in the code.