Fields of Honor Alolan Raichu .

When the player helps the Diglett Trainer find at least 40 Alolan Diglett, the player can get an Alolan Raichu as a gift.

This marks the first time an Alolan Raichu can be obtained in Sword and Shield.
(This statement above excludes any kind of transfer via Pokémon HOME)

This gift cannot be shiny.