Family sharing gift card

I believe there are situations where even though the Organizer's card should automatically be included in a participant's information, that some have reported needing to enter the 3 digit CVV in order to activate this. Trying to redeem the gift card should not have directly required that but it could be a lingering aspect of verifying the Organizer's payment when setting up the child's account and doing something else financial with the childn's account triggered it. I'm kind of guessing here. :-)

If entering the CVV number does not get things working properly, contact Apple about what code is needed.

Refer to this document for ways to contact Apple ➞ Choose your country or region - Official Apple Support

Select your country (also look for "other" regions), then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service by telephone ➞ Contact Apple for support and service - Apple Support

FWIW, my wife, daughter and I are in Family Sharing. All of us redeem Apple Gift Cards to pay for purchases. But from time to time - and it is rare - my wife and daughter had to verify my card. I am the organizer.

The Family Organizer's card may need to be verified sometimes. It should not charge it, and allow the gift card redemption to go through normally.