In the main menu, tap Add Library. Search for your local public library by name, city, or zip code. Select your library from a list of search results. Your library's digital collection has now been added to Sora, and you'll see age-appropriate titles. 

The first time you tap to borrow a title or place a hold, you will be prompted to sign in. You may need to choose your library's name or branch first.  Then enter your library card information and tap Sign in. You only have to sign in once, and Sora will remember your credentials for next time.