If you can find Dubious Roaches, hel eat those. Also Earth worms specificallfy from a vender online that sells food for reptiles and amphibs. NOT FROM A BAIT SHOP.. A pinky once or 2x a month is correct also. Make sure he stays damp. The dryer he is the less likely he is to eat. Make sure he thinks its spring time by keeping him moist and warm. Feeding him very few mice will ensure he lives a long time.
As for the screen top, keep it and cover it with foil, make a few small air holes in it. one big hole for the lamp. But dont allow too many open spots where you can see the screen. This has always worked great for me. Keep an eye on that temp when you do this, But it should trap the heat and humidity in a small 10 gal tank great. I would cut a good size flap in the foil so u can lift it back once a day for a few min if needed to vent more fresh air.
Take the moss out also. Just to be safe, and keep him in the forrest bedding or bed a beast so he can dig a nest. You can use a water dish. Make sure its shallow or he will drown. I never use them i just keep it very damp. But an actual dish seems to ease most peoples mind.
Your froggy is 100% a Cranwellis (Chacoan horned frog) Thats all Petco gets supplied with. Plus you cool photo makes it very clear what he is.
Hope this helps, Bobby,