Mist him twice daily, basking temps should be at least 95, warm zone 85, with a cooler spot to retreat to if needed. Are the dark greens good greens like collard, mustard, escarole? Mix it with some veggies like green beans, squash, sweet potato, cut into small enough pieces. Also top it with some fruit like mango, papaya, apple, just a little bit of fruit, like a salad topping. The Uv should be a high quality UV light that is positioned close enough to him to get a good bit of basking...about 6-12" away from the lizard. You may want to consider get a stool sample checked by a vet for a parasites as well. Adding Nutribac probiotics is good for digestive health.
If the husbandry is good, then his appetite will kick in.