How to use Lexa AI and where does it show up at?

I don’t know how to use Lexa AI? I tried to add a prompt onto the Lexa AI in settings, thinking it would work when I click a unknown word when playing a Netflix show, but nothing.

I added this prompt as I am primarily learning Korean and Japanese:
Chinese word: Provide the equivalent word in simplified chinese and traditional chinese with pinyin for the word as used in this sentence:

At this point, I am not sure if Lexa AI is a not yet finished feature, bug, or if I just have no idea how to use it.