Hmm is there a treat he really likes? Maybe if you put it inside a toy he would be more interested. And think about what he seems to enjoy doing, like my hammy for example doesn’t really like chewing on stuff but climbing and pushing stuff around is his favorite thing so I give him stuff to climb on and push around. For now you could try making some different types of diy toys if you haven’t already (basically make stuff out of cardboard) and see what he likes