You can create an item from any webpage by clicking the save button in the browser toolbar. Sometimes Zotero can't recognize the type of resource you are viewing in your web browser. Even if Zotero can't automatically capture citation info from a certain web pages, you can still add the webpage to your library.
For more information:
Zotero can add items automatically using ISBN number, Digital Object Identifier (DOI), and PubMed ID. Follow the instructions below to save by any of these identifiers.
If you installed the Zotero Connector for Firefox, Safari or Chrome, you are able to save books, journal articles, web pages, etc. directly from your browser to your Zotero library.
To add resources manually, follow the steps below.
If you have a collection of previously downloaded PDFs on your computer, Zotero can help you add citation information for them.
To add PDFs to Zotero and find their metadata, use the following steps:
For more on how this process works, read Zotero's retrieve metadata guide.