In times when the manga and LN are linked, you have to be on the desktop website and click "Other sellers and formats," or "See all formats and editions" for kindle pages, and then the little right-arrows next to each version to reveal hidden formats amazon has linked.
For example, White Cat's Revenge both manga and LN ebook and physical books are linked. See this screenshot album for instructions. https://imgur.com/a/BKx89Ba