App developer David Barnard first noticed the change, and 9to5Mac has confirmed that it's already live. The feature apparently started rolling out last week.

Whoa! Apple added an additional confirmation step for subscriptions. This new alert comes after you confirm with Touch ID/Face ID. I hope they address this in a more elegant way in iOS 13, but I'm thrilled Apple took a definitive step to curb scam subscriptions. 👏🏻 @pschiller pic.twitter.com/oktaEVdx0o — David Barnard (@drbarnard) April 11, 2019

Apple has been refining the App Store subscription process over the past months to keep unscrupulous developers out. In January, the company started banning apps that hide real subscription fees in tiny print to trick you into agreeing to higher amounts than what you're willing to pay.