The Pokémon Pokopia Expansion Pass purchase bonus is 30 rare Pokémetal Ingots.
The bonus is distributed as a code sent by email to eligible purchasers who buy the pass by the stated deadline. The ingots can be used at a workbench, making them a crafting-related reward rather than a new Pokémon, cosmetic outfit, or story location.
The official announcement distinguishes this bonus from the dynamic Ditto print recipe. Pass buyers can claim that recipe in-game, while the 30 rare Pokémetal Ingots are supplied through the purchase-bonus process. Keeping those rewards separate prevents a common mix-up.
The announced code-claim deadline is Tuesday, August 31, 2027. Store or online download-card purchasers can also qualify under the stated conditions, so the reward is not limited only to direct eShop purchases.