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 an IT 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 ID is greyed out in Settings - Apple Support
Tap Settings > Screen Time > Content & Privacy > scroll to Allow Changes and turn on.
- If the device is managed (Settings > General > VPN & Device Management), contact the IT department that is doing the managing.
● If a payment method entry is greyed out and you are a Family Sharing member, you cannot add your own payment method unless you are the Organizer or you turn off Purchase Sharing. See How to share apps and purchases with your family - Apple Support
● Situation where a VPN was preventing action —> Unable to sign out of my Apple ID on my i… - Apple Community
● Situation in which Terms And Conditions in Settings had not been agreed and was blocking access to certain features including automatic backups. —> My icloud and find my iphone are greyed o… - Apple Community
● If you see a message telling you to wait before being able to sign in or out, you may need to read this article about Stolen Device Protection: About Stolen Device Protection for iPhone - Apple Support
