This is a very controversial subject.
There are hundreds of threads on this topic.
Bottom line is that ultralight trailers have thin metal bumpers with weak welds.
The only way to do it safely, is to have a receiver welded and braced to the frame.
But this modification may void the frame warranty.
A search here will give you lots of reading as your question is asked all the time.
Personally, my bikes are too valuable to put them somewhere I can't see them.
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC