Add Pay with Amazon to your Spree Commerce solution.

Add spree_amazon_payments to your Gemfile:

gem 'spree_amazon_payments', github: 'amzn/spree_pay_with_amazon'
gem 'spree_social', github: 'spree-contrib/spree_social', branch: '2-3-stable'

Bundle your dependencies and run the installation generator:

bundle
bundle exec rails g spree_amazon_payments:install
bundle exec rails g spree_social:install

Register for your Amazon Payments account here

You will need to configure Instant Notification Settings in order to accept the callback when a refund is completed. Configure your IPN settings by logging into your Seller Central Account.

The IPN URL will be in the Configuration section of your Spree Commerce instance.

Please see the user guide here for more information