Download a plug-in:
This plugin creates an additional tab in Zotero, where you get a preview of how the reference will appear in a reference list based on the style you have currently selected.
You can download the file from here under the heading "ZoteroPreview". Scroll down to the middle of the page:
This is how it will appear in Zotero after downloading: first how it will look in the bibliography and second the in-text citation ("Individual citation"). At the bottom of this tab view, there is also a function for copying the reference.