This cannot be undone.
Deleting your Social Skills Park account removes your Firebase user, progress, settings, and practice media tied to that account on our servers.
If you only used a guest account on that phone, you still use Profile → Delete account on that same device.
Email support@socialskillspark.com from the Apple or Google address you used to sign in. Write “Delete my Social Skills Park account” and say you cannot use the in-app control. We will verify the account and delete it.
Account deletion does not cancel Premium. Apple keeps charging until you cancel in Settings → Apple ID → Subscriptions.