I use one of those trailers on my old Diamond back mountain bike, and a typical skewer mount holds it fine, but that's a mid motor conversion. There's not the same force on the skewer/wheel like there is with a hub motor
Hub motor axles are rectangular, usually 12 x10 mm, while the hole in the trailer adapter is probably 10mm. So you would have to shape the hole in the above fitting to align properly, After doing that, you would find that the 12 mm washers used on your Ride-1up won't fit in the recessed hole. So you'll also have to cut a rectangular slot in a 10mm washer to fit in that recess.
Next each hub motor is different. Some would allow that bracket to sit flush against the frame, which is best. I think this is what the RIde-1up does, Others have a washer that fits into the axle first, so the bracket fitting would have to sit on top of the washer, Now you have a stack of metal parts with only the washers in contact, which is more prone to work the axle nut loose.
That's the big concern with a hub motor. You have to keep the axle nuts from working loose, or the motor will spin in the frame and destroy the mounting slots.
In summary, you will have enlarge the hole the bracket, and probably fiddle with a washer that fits in the recess. Then yiu have to assess whether it's going to be a safe arrangement. Will the bracket have enough metal afterwards. Will it stay on the axle,
