You can go online to buy an action replay on websites such as amazon. They can cost little or a lot but will be overall worth it because it should make you able to get all Event items, infinite Masterballs and like gold bottle caps in USUM/SM. 100% worth it. Btw you can also hack in Pokémon, but hacked Arceus won’t be legal. You need to use the hack to give yourself the item. Then the Arceus will be legal, even if the item is not.