Searching speech therapists in your area, maybe even asking your doctor! It’s always great to find new ways that can help. I will say (and I speak on behalf of myself and my brother), that speech therapy didn’t really help us a whole lot. You learn things you shouldn’t do, and it helps build confidence a bit (probably more so when you’re a kid). But my brother and I didn’t have overall helpful experiences. We could have went without the speech therapy in all honesty. My stutter is mild, and my brothers is severe. BUT everyone has different experiences, and trying new things is ALWAYS a good thing! If he goes, I really do hope that he finds it helpful and that he can build his confidence! I’m saying this so you know, sending him to speech therapy isn’t going to cure him. It might not even make his speech “improve”. But it’s always nice to learn a few techniques, and to learn that it’s perfectly okay to stutter.