I just drilled a hole big enough to install a typical trailer ball to a riding mower I bought at a garage sale. Now I can use a towbar with the appropriate hitch and it works great. A lot cheaper than anything else on the market.
FWIW: my tow bar is a Brackett TH-5 which was replaced by the Brackett TH-6. I adapted a pair of 7" Plastic wheels to it making it easier to move around. I bought it 9yrs ago when it used to be a lot cheaper than it is today. You could probably get the same results with the cheaper ring hitch Universal Tow Bar.