Best False CrossBar for e-Bike?

[oldpeddler]

I've got a Toyota Prius and Saris Bones rack. Can't seem to juggle a Haibike SDuro ladies (2019) model on. Note that most false bars quote maximum load of 15 Kg, clealy not enough even with battery removed. Anyone solved a similar situation?

 

[BazP]

I got a tow ball and rack for my Prius which I found much better than a hanging rack, which I presume the Saris is.