Click on the “+” button from the main window.
In the Import panel search field, enter your search terms and the source from the drop-down menu (arXiv, Google Scholar, IEEE Xplore, JSTOR, PubMed, or ScienceDirect). You can then click on particular entries from the results page to refine your selection. Finally, click on “Import” to import these documents to your library.
Note that you can still use the Zotero Web Translators from your browser (c.f. https://www.zotero.org/support/getting_stuff_into_your_library).