I have fox too. My neighbor put up a sign on our road in front of our houses “Caution, Fox Crossing”. I have 1/2 inch hardware cloth covering my 6 foot tall run. I also have it wrapping the entire run walls because chicken wire can be ripped by fox, raccoon, dog, and a myriad of other predators. It isn’t meant to keep predators out. It’s meant to keep chickens in. The other reason is because any opening one inch or bigger will allow raccoons to reach their very tiny hands inside and grab a bird, pull it’s head close, and eat it’s head. Other predators can squeeze through those openings. Mice, rats, many many. My biggest personal fear is snakes, so the same thing goes for the apron.
Anyway that’s what I do for my fox and other predator problem. I still haven’t figured out how to configure electric fence due to property configuration. Meanwhile my run “frame” is chain link dog run in hopes it at least slows down black bear enough for me to be able to chase one off if they try. Yes, I had one walking through my yard 10 feet from the run door as I was exiting the run. I was able to scare it off before I broke into some serious shakes. Scary stuff.