Hello, I purchased a computer for online classes in 2024 do I add that cost under "Books and materials not required to be purchased from the school?"

Yes provided it meets the qualification.  Publication 970 states:  The purchase of computer or peripheral equipment, computer software, or Internet access and related services if it is to be used primarily by the beneficiary during any of the years the beneficiary is enrolled at an eligible postsecondary school. (This doesn’t include expenses for computer software for sports, games, or hobbies unless the software is predominantly educational in nature.) 

Q. do I add that cost under "Books and materials not required to be purchased from the school?"

A. Yes. That is the correct place.