You have to download it from here https://zennolab.com/discussion/threads/zennoposter-chrome-edition.53663/, it's a whole new zenno software, "Important: Stable ZennoPoster release 5.25.0.0 available in user area. It does not have Chrome Engine." So you have to download it from there and runn it, and you will have 2 zenno posters , one with mozilla and one with chrome.
To be able to use ZennoPoster Chrome Edition, you should have valid ZennoPoster license with latest updates. If you don't have updates, you won't get it.