Sign out of apple id

Go to Settings > Screen Time > Contents & Privacy Restrictions > Account Changes, and make sure it is set to Allow.

Are you a member of a Family Sharing plan? It would be the Organizer of the plan that can prevent Account Changes on your device and you will not be able to override it on your phone.

Check these possibilities:

● If an app or feature on your device is not working, not appearing, or is restricted (grayed out), a frequent reason is it may have been disabled using Screen Time, or by a technology administrator if you are using a device owned by an employer or educational institution.

- Read this support article If your Apple ID or other options are greyed out in Settings —> If your Apple Account is grayed out in Settings, or you can't sign out - Apple Support

Tap your Settings app > Screen Time > Content & Privacy Restrictions > scroll to Allow Changes and turn on.

- If the device is managed (check: Settings > General > VPN (or Profiles & Device Management), contact the technology department of the organization that is doing the managing.

● Situation where a VPN was preventing action —> Unable to sign out of my Apple ID on my i… - Apple Community