The derailleur has two screws, the low adjusting screw which controls how far the derailleur moves towards the wheel and the high adjusting screw which controls how far it can move away from the wheel.

Adjust these screws with the screwdriver until it positions the derailleur in such a way that the front handle (shown earlier) can be used to switch from the highest to the lowest chainrings/sprockets on the rear crankset