To use the AB as an independent effect, try wiring it like this:
Install a jumper between the “I” and “O” pads on the AB. You will not be using that loop.
Wire the IN jack > Order switch IN. Wire the AB and Distortion IN and OUT to the Order switch. Wire the Order switch OUT > OUT jack. Now you can select AB> DIST or DIST > AB.
I hope this is clear.