So I know this is not the correct way to put the nut on but it will not go on the other way around
Any ideas how I can fix this ,
The thread is too deep on the opposite (correct way)
The axle needs to be moved to the point where it is more central. But remember, usually more thread is needed on the RH side, especially if Derailleur type gears are being used....
(I am assuming that you still have the correct axle!).
Its not difficult to do, but difficult to explain as there are different systems and bearings on ebikes....!
It may even have been mounted the wrong way round by someone, depending upon the style.
If you do not know how, then its a job for the LBS in your area.....at the most, 1 - 2 hours work in my estimation!
It looks to be the RH side in the photo (I took it to be the lefthand side before!), and to my mind that is the wrong side for a trailer hitch IMO.
I am going to watch and see what you eventually do to fix it! Maybe I can learn something too!
Best of luck.
Andy
PS Or is the photo upside down????