Ask to buy isn't on my child's ipad

Just setting up an iPad which I've bought for my child.

I set it in child mode for more control, however I didn't realise you need another apple device to control 'ask to buy' app downloads. (I dont currently have anothet apple product) So I thought I'd just turn the 'ask to buy' option off. However, the -ask to buy button isn't even on the iPad under family member organiser. So I can't unselect it. I've tried to resent the whole iPad but icloud keeps setting it back up I the same mode.