It is not necessary to note that you have used an eBook or audiobook when the content is the same as a physical book. However, you should distinguish between the eBook or audiobook and the print version IF the content is different or abridged, or if you would like to cite the narrator of an audiobook.
For more information, see the Publication Manual of the American Psychological Association, 7th ed.
Citations for e-books closely resemble those for physical books. Simply indicate that the book in question is an e-book by putting the term "e-book" in the "version" slot of the MLA template (i.e., after the author, the title of the source, the title of the container, and the names of any other contributors).
While MLA 8th edition recommends including URLs, make sure the URL you use is a permalink or use a DOI. Because library databases require a login, the URL in the address bar may stop working after the session ends.
For more information, see the MLA Handbook, 8th ed.