On your iPhone, open the Settings app, then tap [your name].
Tap Sign in with Apple.
Select 8 Ball Champions, then tap Delete. Follow the onscreen steps to confirm that you want to stop using Sign in with Apple for 8 Ball Champions.
What happens if you stop using Sign in with Apple with an app
When you stop using your Apple Account with an app, you’re signed out of the app on your device. The next time you visit the app or its associated website, you can either select Sign in with Apple to sign in again, or create a new account.
If you choose to use Sign in with Apple again, you’re signed in to the same account that you previously used. Some apps might let you create a new password for your existing account so you can sign in again without using your Apple Account.
If you delete your account in an app where you use Sign in with Apple, you might receive an email from Apple that the app has revoked your Sign in with Apple account. If you want to create a new account with that app, you have to share your name and email address with the app again or create a new account using Sign in with Apple.