With my son we hooked a python API to minecraft, you can then write some kind of bot. He really had fun with it. Being able to see things in a 3d world he knows with 2 lines of code is what got him hooked. He learned python to build things, not to learn to code.

I think you should use a platform with immediate results like this and forget about coding. There is also dreams on ps5 which is great. Try to find a way to scripting or modding a game he loves. It is really rewarding.

Also, talk about it when you are with him, in commute, at dinner...