Ability Capsule appears in 5 version groups since Generation VI, a Vitamins item in the Medicine pocket
PokéAPI item 685 of 2,223, Vitamins category, Medicine pocket
Effect, in PokéAPI's words
Ability Capsule: “Switches a Pokémon between its two possible (non-Hidden) Abilities.”
Games
Ability Capsule is listed in the text of 5 version groups, first in Generation VI
Game index by generation
IIIIIIIVVVIVIIVIIIIX
Named in
X and YSun and MoonUltra Sun and Ultra MoonLet's Go Pikachu and Let's Go EeveeSword and Shield