The Yakima OnRamp Bike Rack for 2 Electric Bikes - 2" Hitches - Frame Mount # Y36FR is the correct model you're looking for, that will fit on a 2" hitch. The OnRamp can be used on vehicles, trailers, RVs or flat towed vehicles, so they're a great solution for whatever you need to use it with.
I've linked a review of this video of this bike rack for you to check out. view full answer...