online course？

I'd suggest checking with his PD or the child development specialist first, since they can assess whether online courses would actually benefit him given his specific ADHD profile. Some kids do well with structured online learning while others find the lack of physical interaction harder to manage, so it really depends on your child's needs and learning style. You might also want to explore if his school has any support programmes or recommendations, since teachers often know what works best for each child in a classroom setting.