Dr. Lava on X: "Pokemon Gen 4 contained a key item never made available to fans -- the Azure Flute, which would have granted access to the Hall of Origin and a
Platinum
Semi-legit Azure Flute (Received using Mystery Gift Exploit) : r/ pokemonplatinum
Pokémon Platinum Events Service. | eBay
Pokemon Platinum | Part 79: How to get Rotom + Secret Key - YouTube
Team Galactic Headquarters - Pokemon Diamond, Pearl and Platinum Guide - IGN