iOS 8.3 - App Store Password Restrictions

After upgrading to iOS 8.3 and opening the App Store, it prompted me to choose between "Enter Password Immediately" or "After 15 minutes". I blindly clicked one thinking I could change it later.

However now I can't find where to set this. I found this tech article, Use restrictions to prevent purchasing on your iPhone, iPad, or iPod touch - Apple Support however it seems to be out of date as there is no option for "Require Password" on my phone now! Does anyone at Apple do regression testing?

Anyone know where I can change this setting?

Thanks