Search without assuming a fixed spot
The key is the stated objective inside the Potato Mountain: peel potatoes to find the hidden key. The official description does not state where it spawns or whether its location is fixed.
Use in the current game
Work through the area you can access and follow the game’s current interaction feedback. If you play again, compare your own observations rather than assuming the previous key location repeats. Treat community tips as version-specific until reproduced in the current game.