Plug your iPhone or iPad into your computer using a USB cable.
Click the (a small smartphone symbol) that appears in the top-left area of the iTunes window. Configure Sync Settings : In the left-hand sidebar, under "Settings," click on Books . Check the box for Sync Books .
On modern Macs, iTunes has been replaced. The process is now handled through the desktop environment:
If you have book files (typically in or .pdf format) on your computer, follow these steps to move them to your device: Add Books to the iTunes Library : Open iTunes on your PC.
To avoid cables entirely, you can simply upload your books to on your computer. Once uploaded, open the Files app on your iPhone, tap the book file, and it will automatically open and save into your Apple Books library.
: Select your device in the Finder sidebar, go to the Books tab, check Sync books onto [Device Name] , and click Apply . Cloud Option: iCloud Drive