Perhaps you are talking about the Chessable course by Maurice Ashley based on "How to Reassess Your Chess" by Jeremy Silman.
I have never heard that it comes with a separate e-book. The course is sort of an interactive ebook.
This was a news release about it:
https://www.chess.com/news/view/chessable-course-how-to-reassess-your-chess
I bought the Jeremy Silverman and Maurice Ashley course thing. I want to read the e-book that comes along with it. How do I do this…? Where can I find? Thanks