help with my age update

It can be that your parents must help you with updating your age

To change a birth date to any age below 13*, the account must be a member of a Family Sharing group, and the family organizer must approve the change. Follow the steps to change a birth date on the web. You can also create a new Apple Account for a child.

To change a birth date of any child account set to an age below 13*, you might have to wait for the account to naturally age up. If you see “your birth date cannot be changed to this date”, you can’t change to a birth date that would no longer be a child account.*

See this link for further reference

Update the birth date associated with your Apple Account - Apple Support

This can happen, your parent need to update it

To change a birth date to any age below 13*, the account must be a member of a Family Sharing group, and the family organizer must approve the change. Follow the steps to change a birth date on the web. You can also create a new Apple Account for a child.

To change a birth date of any child account set to an age below 13*, you might have to wait for the account to naturally age up. If you see “your birth date cannot be changed to this date”, you can’t change to a birth date that would no longer be a child account.*

Have you tried restarting your device? That gets it to take a fresh look at account settings.