Hello freelancers

I am an Indian freelance content writer. I recently got an opportunity to write an autobiography of two Indian people with their weight loss journey.

I have written blogs, articles and social media posts, but never a book. I still want to give it a shot because I can write the book plus I want to experience writing a book.

But the question is, I don't know how much to charge for writing an autobiography. I am not an editor so I can't edit that piece either. Maybe the publishing house will.

My client have said that they will give me credit for the book. So shall I charge a % of revenue of whatever they earn from selling the book? How much shall I charge for writing?

I would really appreciate any advice regarding this. Thanks 😊