title_body: How to add a clickable table of contents in a book bought from Amazon Kindle?
upvoted_answer: If your book isn't DRM-protected or you manage to DeDRM it, you could convert it to an epub book with Calibre, regenerate the TOC from all headings and convert it back to an azw3 or kfx book. (If the original book is an azw3 book you could also directly edit it with Calibre Editor.) 
  Obviously, this method will only work if all headings were marked with h1..h6 tags.