I just tried out this browser extension on Chrome (it's available for Firefox, too). When you search for a book on Amazon, it shows if the book is available at your local library. How cool is that!?!
https://www.cnet.com/how-to/this-browser-extension-shows-you-which-amazon-books-are-available-free-at-your-local-library/?fbclid=IwAR2KV41GqzVM_Oly57WbUBF1fJULigUgQ0mHKhnaly-XcOf11pxyJrJ1uBI