Q: I cannot find the option for Ask To Buy in my settings. How can I set up the Ask to Buy option for my daughter?

I have the Family Sharing enabled for myself, my husband, and my teenage daughter. I thought I had it set up that my daughter needed mine or my husband's ok to make a purchase. However, today I got an email stating my daughter made a purchase without my knowledge. When I went into my settingson my iPad, then clicked into my iCloud, and clicked on my daughter's name, it does not show the option for Ask To Buy. How do I set up the Ask to Buy for my daughter?