Where do you get the key for cavern isle cave horse isle 2?

In "Horse Isle 2," you can obtain the key for Cavern Isle Cave by completing a quest given by an NPC in the game. This usually involves finding specific items or completing tasks related to the cave. Once you fulfill the quest requirements, the NPC will reward you with the key, allowing you access to the cave. Make sure to explore thoroughly and check in with various characters for clues!