A 2-phase motor should have 4 wires with one on each end of the 2 coils.
Connect one coil to A0 and A1 (pins 20 and 22) and connect the other coil to B0 and B1 (pins 24 and 26).
Please note that if the direction of motion does not match what you intended, you can swap one of the coil connections (B1 and B0 rather than B0 and B1). Or you can account for the negative rotation in software.