How to turn off two factor authentication?

If this is a new Apple ID, or two factor was turned in more than two weeks ago, You cannot.

”If you're already using two-factor authentication with your Apple ID, you can't turn it off. If you updated to two-factor authentication inadvertently, you can turn it off within two weeks of enrollment. “ Two-factor authentication for Apple ID - Apple Support

Thanks. You have restrictions turned on. Go to Settings > Screen Time > Content & Privacy Restrictions > Content Restrictions to allow changes for the Apple ID in settings again.

Why can’t you select sign out? Is it grayed out? Do you get an error message?