See this article (1) to turn it on - you’ll need to go to settings, language, turn on the feature and select your native language under “do not translate”. After that, long press on a message and choose ‘translate’.

Here on iOS, the built in Apple Translator tells me it can’t translate Ukrainian, on Android may be better.

That’s not too big a problem; the channel linked above is mostly in Russian.

1: https://androidcure.com/translate-messages-in-telegram-on-an...