Pokémon Sword and Shield add a bunch of new regional variants to the mix, including an Ice-type version of Black and White’s Darumaka and Darmanitan.
The Pokémon is exclusive to Sword and can be found in either Route 8 or 10. But the way in which you evolve it is different in this generation.
Unlike in Black and White, where you could evolve a Darumaka into a Darmanitan simply by leveling up, Sword and Shield force you to evolve its Galar counterpart by using an evolution stone.
The stone that you’ll need to use is an Ice Stone, which can be found on Route 9. After obtaining the Rotom Bike’s Surf feature, go into the water and move to the upper-right corner. The stone can be found sparkling near the iceberg.
Then it’s a simple case of using the stone on the Galar Daramuka to have it evolve. You don’t need to worry about levels because you can evolve it whenever you like.