Little Stone Museum is published by 4Theory Games. This page explains how to delete the account you sign in to Little Stone Museum with, and what happens to your data when you do. If you never signed in, you have no account and there is nothing on our server to delete.
The account is deleted at once. Nobody has to approve it. The game stays on your phone and you keep playing as a guest.
If you no longer have the game, write to support@4theorygames.com and tell us your nickname. We will ask you to prove the account is yours, then delete it within a month of your email at the latest.
Nothing else about you remains on our server. The game on your phone keeps its local save and settings until you uninstall the app.