The EULA is also a bit more specific about it (and so rules over the FAQ), particularly under the 4. Royalty section.
From what I understand, if your game is completely free to play, free from ads, and players cannot buy any form of in-game items, subscriptions, or benefits, then you don’t have to pay royalties. However, as soon as you start earning money from your game, you’ll have to keep track of the gross revenue and pay Epic the due royalties for every quarter that you make more than $3000 from it.