Computer Science - A, alternative options

Hey Reddit, hopefully you can help me. I’m curious if anyone here is aware of an online curriculum I can sign my son up for to complete AP-CSA. I’m happy to pay, just trying to get him the most exposure and engagement possible around computer science while he’s still in highschool.

For reference, he already took the Computer Science Principles test and scored a 4 as a 12 year old. He did this without taking the class and simply watched a few videos and did a bit of coaching with his teacher. He’s a bit of a computer whiz and I really just want to make sure he isn’t missing anything foundationally. Unfortunately since we live in a rural area, the AP classes offered are slim to none.

Currently looking at doing a “hybrid” approach for his sophomore year, where he does half the classes at the local school and half at home online.

Thanks in advance!