I use the Libby app with with free audio book checkouts from my local library’s account.
I also use Audible - the app is free, I pay $15/mo for one credit per month plus access to the Plus catalog, which has a lot of free books.
Yes, Libby is great if one’s library subscribes to it. Not only is it great for audiobooks but if one has a kindle books can be download for use on a Kindle as well.