Unfortunately, the Thule bike, linked above (Thule EasyFold XT 2 Hitch Bike Rack, Black), has multiple complaints about suitability to Rad Power Bikes (and ebikes in general)...
"It pains me to give Thule such a low review for this bike rack, but my observation is they missed the mark on what Thule is famous for; quality engineering. I bought the rack for two e-bikes and in particularly to accommodate the weight and tire size. My RadPower e-bikes are 65 lbs each and have 4". Fat tires. The specifications claim up to 65lbs and tires up to 4.7". Thule was selected for my new bike rack based on my experience with previous Thule racks I've owned for their thorough engineering.
The bike rack width is insufficient to accommodate my e-bikes without squeezing them together even though the tire width of 4" that is below the max designed width limit of 4.7". To get the tires to be more on the rack than the edge, I put the first bike on, secure it. I put the second bike on and have someone lean the bike out, secure the wheels, and then squeeze it into the first bike and attach the clamp. "
"It pains me to give Thule such a low review for this bike rack, but my observation is they missed the mark on what Thule is famous for; quality engineering. I bought the rack for two e-bikes and in particularly to accommodate the weight and tire size. My RadPower e-bikes are 65 lbs each and have 4". Fat tires. The specifications claim up to 65lbs and tires up to 4.7". Thule was selected for my new bike rack based on my experience with previous Thule racks I've owned for their thorough engineering.
The bike rack width is insufficient to accommodate my e-bikes without squeezing them together even though the tire width of 4" that is below the max designed width limit of 4.7". To get the tires to be more on the rack than the edge, I put the first bike on, secure it. I put the second bike on and have someone lean the bike out, secure the wheels, and then squeeze it into the first bike and attach the clamp. "