If he doesn’t seem like he’s interested much in his hay you can try different types of grass hay. Timothy, orchard, oat, meadow, and bermuda are all options. Since he is a baby he can also have alfalfa hay if his pellet isn’t alfalfa based, but around a year old he would need to switch to grass hay. What kind of pellet and hay do you have him on? You can also try hay cubes or hay that has herbs in it to make it more enticing (such as Oxbow’s Botanical hay), just avoid any hay with other things added to it besides herbs such as sweet potato, seeds, nuts, or fruit chunks (fruit is okay for rabbits in small amounts but too sugary to be fed all the time).
Also, at his vet appointment make sure your vet uses a special tool to check his back teeth. If he has any tooth problems it’s important that they get caught early on. (Though it is unlikely he would have one just yet, that could be a possibility for why he doesn’t eat much hay). Are you planning on having him neutered when he gets old enough? I second the pic request, I’m sure he’s a cutie 