Use the EXTRA field with your stand-alone Zotero, to enter the text of your annotation.
Choose APA or Chicago style with annotations. MLA style annotated is also available with file download.
Chicago Style Annotated Bibliography Using Zotero, by Beth Royall, librarian at West Virginia University (YouTube, September 2017)
Use the ABSTRACT field with RefWorks on the web, to enter the text of your annotation.
An easy way to find MLA, APA, or Chicago style is to search for the word "annotated."
The ProQuest RefWorks YouTube channel includes a guide to creating a bibliography.