Recently, I got an invitation from a professor to contribute a chapter in one of his/her upcoming books. I am a novice in this field. I am still a student but simultaneously I do not want to lose this opportunity. I have a few published articles. I am quite confused about the content of the chapter. Can I use my results from the accepted manuscript and add them as chapter content of the book? Is it totally ethical? Kindly help me. Suggestions are most welcome by heart. Thanks a lot.
P.S. Checked their profile. They are some professors in an university but I never met them. And they did not talk about whether its a normal chapter or some proceeding type chapter in the book. And no mention of money also.