The "Pay with Amazon" feature requires https to be properly set up for your store. Also note that a new required setting - "Client ID" - has been added for "Pay with Amazon"; this setting must be adjusted to ensure that your store's "Pay with Amazon" integration functions correctly. To obtain your Client ID, register your website as an application on the Login with Amazon App Console (http://login.amazon.com/manageApps). For more information, see the Login with Amazon Getting Started Guide (https://images-na.ssl-images-amazon.com/images/G/01/lwa/dev/docs/website-gsg._TTH_.pdf).