Before you add a link to a library ebook to Canvas, be sure to check the number of users. Especially if the book is going to be used by the entire class at the same time. If you can't determine the number of users, you can ask your subject librarian.
Once you've found an ebook in IUCAT, you have a couple of options for getting a persistent/stable URL to add to your Canvas course site.
There are a couple of ways to add an e-book to your Canvas course site.