How do you you get to hotzeplotz isle on HorseIsle

You must do a few quests for the King by talking to Grey Slate on Hare Isle first. After that, Grey Slate will send you on a quest to talk to the King, and you're able to go whenever you wish, but before each time you must have Grey Slate's coffee from Art Isle (This is until you complete the King's other Quests on his isle first)