Q: How do I prove I'm an adult without a credit card? We don't keep credit cards and it says I need one to army 9year old to my family sharing plan so she has to ask permission for purchases.

I Am in the same boat you are in. I don't use credit cards. I talked with an apple care guy today and that came up.  I have an 11 year old. He said the rules currently requir a credit card. A debit card will not work. Kind of stinks.  considering the restrictions family sharing puts on the device for under 18 I set my kids age at 13. So that I could share apps. I don't like family share because now I have to approve every free app as well.

I used a pre-paid (gift card) from American express.

I Had the same problem but was able to get around it by temporarally using my parents credit card to set up the accounts and then changed the payment method back to my debit card straight after. Can you borrow someone's card details to set it up?