Hello, I have read Creating A Localization Ready Game in UE4: Part 1-Text - Unreal Engine but I still don’t know how to add other culture texts. Is there any step-by-step uide to setting it up?

You’ll probably find this forum post useful.

Thanks! One more question: is it possible to change cultures in runtime?

It is.

Code-wise you just need to call FInternationalization::Get().SetCurrentCulture(“ja-JP”).

Command prompt-wise you can use the exe command CULTURE=ja-JP