Hey there LSKSFSGS,
Thanks for reaching out to the Apple Support Communities. If needing help with removing your Twitter account that was set up using Sign in with Apple, check out the steps below:
Stop using Sign in with Apple with an app
1. On your iPhone, go to Settings, then tap your name.
2. Tap Password & Security > Apps Using Apple ID.
3. Select the app or developer, then tap Stop Using Apple ID.
When you stop using your Apple ID 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 ID.
You can find these steps, and more details on managing apps that use Sign in with Apple at this link here: Manage the apps that you use with Sign in with Apple - Apple Support
We hope that's able to help.
Take care!