Don't overlook the weight of the bikes as most are going to weigh from 50 to 70 lbs each and your bike rack needs to be able to support the load of two bikes and your back is going to need to be able to handle the weight when loading and unloading the bikes.

Some bike racks like the one from Thule, include provision for a ramp. Depending on the height off the ground of the hitch receiver the ramp may or may not be usable. Most racks that can support the weight of 2 heavy e-bikes require a 2" hitch receiver on the vehicle.