Honestly, I wouldn't call it plagiarism. You're using the prompt for personal purposes, to better understand the material. If you were copying his text and passing it off as your own, then yeah, that would be not cool. But using his approach with interactive visualizations as a source of inspiration for your own learning materials is fine. If you ever decide to put it out in the open, just mention that you took inspiration from his style and include a link to his work.