If you already own a myQ-connected smart garage, all you need to do is download the Key app in order to sync your Amazon and myQ accounts. Then, next time you order something on Amazon, select "in-garage" delivery at checkout. If you don't have a myQ connected garage, Amazon is offering a limited time discount on a myQ Smart Garage hub for $49.99 (the system is normally $79.99).
"Porch pirates" are a common problem for Amazon as well as delivery companies like UPS and Fed Ex, so an expansion of the Key program to work with customers' garages is a logical move. If you're especially concerned about security, you can also add an Amazon Cloud Cam to your myQ smart garage hub. This will let you view footage of the entire package delivery. While the smart garage setup may seem paranoid or excessive to some, it may be a worthwhile investment for the growing number of victims of porch piracy.
Update, 4/23/19, 11:50AM ET: This post originally contained references to Amazon's Flex delivery program and its drivers having to take "selfies" as a security authentication measure. We've removed them, as the Flex selfies are meant to reduce fraudulent account usage rather than safeguard package security as the Key program does.