Propose a new game for the leaderboard.
Ask the site admin for the QR SDK integration guide if you haven't built your game's on-device QR submission yet. This form captures the same spec that guide's submission template asks for -- fill it out from your own finalized payload design.
The two extras are just extra art for your game's own leaderboard page later (a title screenshot, gameplay GIF, etc.) -- not shown on the main grid tile, and not built into a page automatically (see the note below).