It's on sale - so it's participating.
You can always go here: On Sale - and scroll down all the 1367 games until you find yours.
Mind you, nobody can actually buy your game for the sale price, because the minimum payment is $1.
From what I understand, when a project is <1$ during a sale, users have the option of adding more projects until the price is 1$ or above, alternatively they can tip the difference and pay 1$.
I’m not sure if that’s the case with all payment options, or only some of them, or if this is on certain regions only.