The library makes a proxy server available for off-campus access to licensed resources that use IP-based authentication. Accessing these resources through the library website will send you through the proxy automatically, but using the proxy is more difficult when accessing resources directly through a publisher's website or Google Scholar.
Zotero will store the proxy server's URL and send you through the proxy automatically when you access publisher websites, databases, and other library-licensed resources. This behavior is enabled by default; the first time you access a resource using the proxy Zotero will detect it and will prompt you to store the proxy server's URL. Subsequent visits to the same resource will be routed through the proxy automatically.
For more information on proxy servers, see Proxies Preferences