For me this popped in wordament (adventure). You can use your keyboard to type words, which is much faster then using the mouse. Use this site to find the best words. I'm pretty sure the amount of points this site claims are not in line with what you get in wordament, but anyway, play a few games and this one should unlock pretty soon if you make the longest and rarest words.
https://words-solver.com/wordament-cheat/