If you delete the game without performing a transfer, you will not be able to recover the game. For steps on how to transfer, see the article, "How do I generate a Transfer Password for Pokémon Shuffle Mobile?"
Please note: The game is not completely stored on our game server. There is no way to recover a deleted game if you have not first generated a transfer password.
For more information, please see https://support.pokemon.com/hc/en-us/articles/360000698274
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