Zotero Connector is a browser extension or add-on for Chrome, Firefox, Safari, and Edge. When you’re searching for an article online, you can click on the Zotero Connector button to add the article to Zotero Standalone. Install Zotero Connector from the Zotero website.
Zotero Online is the only way to sync or share your citations. Create a free Zotero account from the Zotero website and then sync it by adding your username and password to Zotero Standalone. Go to Edit > Preferences > Sync. Use your Caltech email address to get unlimited storage courtesy of the Caltech library!