If you want to grab a Shiny Meloetta for yourself, you’re going to have to first own Pokémon Scarlet and Violet, and both parts of The Hidden Treasure of Area Zero DLC.
Nintendo and Game Freak will reward you with a free Shiny Meloetta in Pokémon Home, if you’ve completed the Pokédex for Paldea, Kitakami, and Blueberry Academy. In other words, to get your ...