I can't find the Yandex Translator button?

There is no such extension. If you are referring to the Yandex Translate component, this has been replaced with Translator. Use this instead, the functionality in your project will be the same.

Greetings, Could you please help me? I am designing an app to translate into other languages, but I can't find the Yandex Translator function. Thank you very much.

這次會用到三個新東西，語音辨視、文字轉語音以及 Yandex翻譯的元件，這三個元件組合一下，就可以做出一個簡單的即時翻譯的APP。

在App Inventor中有很多好用的元件工具， 本次將使用「Yandex文字翻譯元件」來進行文字翻譯。 如不指定語言，Yandex會偵測來源的語言，如有指定語言（en-zh），便會依指定將來源語言Source（English）翻譯成目標語言Target（Chinese）。

This video tells you how to create language translate app in MIT App Inventor using Yandex Translate in App Inventor.