Hi,
When they say "move it", they really mean "bend it". First get the rear wheel off the ground and try shifting through all the gears (with the wheel turning). If you get all the gears, then it is fine. If the "U" bar prevents the shifter from coming far enough out from the bike, and the chain will not get on the smallest gear, then you have to bend the "U" to allow clearance. Best bet is a large pliers, or an adjustable wrench. Or use a screwdriver or other flat lever to pry the bottom of the "U" away from the bike. Just a little, enough to let the shifter go into the smallest gear.
What is really for it to protect the derailleur if the bike falls over. Good Luck. I think you will really enjoy the ebike experience .