If he's only 3 months old, he REALLY NEEDS LOTS OF HIGH QUALITY LIVE INSECTS and if he eats his greens and grated veg it's a bonus.
He needs AT LEAST two live insect feeds (as many insects as he'll eat per sitting given to him a few at a time (not all dumped in with him at once) , THREE live insect meals per day at 3 months old is better.
Recommend the following insects as staples
BSF maggots (phoenix worms)
small (about 1.5in long) to medium (about 2in long) silkworms
1/3 size crickets who have been gutloaded with calcium rich greens and are dusted with calcium dust or similar sized roaches or locusts. Do NOT give insects that are too big.
Other bugs sold commercially are NOT recommend for a 3 month old even as occasional treats.
Offer him fresh greens and grated veg / salad daily , he may or may not nibble on these , suggest if he develops a taste for them , that you give the greens and salad AFTER he's had at least 1 big meal of live insects, else he'll fill up on greens and salad and have no room left for his all important bugs.
Make sure his basking temp, his warm zone temp, UVA and UVB are right else he'll not be warm enough to have a high metabolic rate (become hungry) and wont be able to digest his food properly.
If his UV is not intense enough he'll not be getting sufficient UVA to have a strong apetite, and he wont get enough UVB to metabolise dietary calcium and produce VitD.
I suggest you check the temperatures, the lighting schedule (needs lights on 15hr per day), and check you have the right intensity UV ( needs to be rated at least 10% UVB + 30% UVA and be close enough to be effective).
At 3 months old Peppa and Toothless were EACH eating up to 20 med/small (1/3 sized) crickets + up to 6 medium silkworms + some greens and grated carrot per day ,split over an am and a pm meal. The larger meal was the mostly crickets in the am (about 10am , their lights come on 6am). I only handfeed them 2 - 3 crickets each in the am at the start of the am feeding as a bonding ritual.