From the announcement:
Zotero makes it easy to collect research materials with a single click as you browse the web, but what do you do when you want to add a real, physical book to your Zotero library?
If you have an iPhone or iPad running iOS 12, you can now save a book to Zotero just by scanning its barcode…
This feature takes advantage of the new Shortcuts functionality in iOS 12, which can chain together series of actions to perform tasks.
To get started, you’ll first need to install Apple’s Shortcuts app, if you don’t yet have it on your iPhone or iPad.