How to enable Localization preview

I made localization with localization dasboard.

I can easy change language of the game using c++, using this command,

and it is working, but only on stand alone, similar like fullscreen mode works only on build.

but widget menu where is preview language i have only option none, and i can’t find how to enable this option.
pls help

set “Loading Policy” be “Game” in localization dasboard and restart UE4