Izip Path + 2015

[alvin]

I am a newbie to electric bikes and I just bought a used Path + 2015. The owner's manual is not terribly helpful about the gear shift system. I keep pushing the levers while riding to shift gears and nothing happens. I don't know if it needs adjustment. Supposedly it was gone over by a mechanic before sending it out. Is there a method to shifting gears on this bike? Thanks for any help.