HT Games
Nowhere — it doesn't exist. Minecraft was never released for Wii (only Wii U, 2015, as Minecraft: Wii U Edition, delisted 2019).
If you have a Wii U, the game is delisted — cannot buy new. Used physical copies ($50–$100) exist on eBay but require system transfer from another Wii U that already owns it.
Avoid unofficial "Wii Minecraft" downloads — they're malware or Minecraft PE ports that don't work.