In this guide, you will learn how to restore the save data and how to backup your Island in Animal Crossing New Horizons.
The first thing you will need to do is start the game, and when it says Press, you have to look on the bottom left side of the screen where you will see the Settings option; you have to click on it, as shown in the image below.
You will find three different options there; you have to go to the island backup option, turn it on, and update when you are not playing. It will use your Nintendo switch to update your game, and you need to make sure to be connected with the internet network; otherwise, your game will not update.
You can only restore this data when your Nintendo switch is broken or lost, which means you need to have a new Nintendo switch and then send a request to Nintendo to backup your island in the game.
If you share your island with any other player, you have to delete all of his data on your island. You have to go to your settings and delete the save settings for the whole game, but this is only for the specific players on your island except you.