If I choose a style, how could I add the style? Due to the fact, there is no "ok" button. Do you know what I mean? In this version there is a "ok" button: https://www.zotero.org/support/de/preferences/cite
That's just a list of the styles you already have installed. If you want to install a new one from the Zotero Style Repository, you can click "Get additional styles…" and select it from the page that pops up.
https://www.zotero.org/support/preferences/cite
If I choose a style, how could I add the style? Due to the fact, there is no "ok" button. Do you know what I mean? In this version there is a "ok" button: https://www.zotero.org/support/de/preferences/cite