I had a couple box fish and a few puffers over the years and even the most stubborn eater couldn't resist live ghost shrimp. Buy a dozen from anyplace you can find them locally and just let them crawl around on the bottom. They're freshwater shrimp but should be able to live a few hours in the tank. If you can't find ghost shrimp bite the bullet and buy a couple peppermint or even a pistol shrimp. Once he gets eating again he should gradually eat frozen foods.
Also be aware that these fish are prone to internal parasites so you might look into some meds to treat them. Some show no other symptoms than loss of appetite.
Good luck, beautiful fish.
Also be aware that these fish are prone to internal parasites so you might look into some meds to treat them. Some show no other symptoms than loss of appetite.
Good luck, beautiful fish.