Access your inventory with X, or a two finger tap if you're on mobile. You can then see the instructions on the sticky notes.
All the note says is (essentially) ''check the back of Room 18''.Then, in said room, all I get is a (placeholder)Lollipop. I can NOT find where to go from there... way too obscure.
Interact with the server in room 18. And then, check your inventory.
