You may want to cite references while writing a paper. The plugin adds a Zotero toolbar to your word processor that allows you to add citations to your document. The word processor plugins are bundled with Zotero and should be installed automatically for each supported word processor on your computer when you first start Zotero. You should not need to install it separately, but just in case you need to do that, here is the link:
https://www.zotero.org/support/word_processor_plugin_installation
When you are in Microsoft Word, select the “Zotero” tab on the top. You will see this toolbar -