My web site currently has AmazonSimplePay(discontinued). So, I'm trying to replace it PayWithAmazon. I just added a sandbox expressButton for PayWithAmazon code to my web page and tested, it seemed to returned back to my site and showed the transaction in the Amazon dashboard. However, the AmazonSimplePay(that I want to replace), currently integrated on my website, takes the Amazon purchase and adds credits to that paying customer's web site account - in order to use those credits on my web site. So, my question is can PayWithAmazon Button Integration be used to replace my present SimplePay integration, or will I need API Custom Integration for PayWithAmazon to replace my SimplePay integration? Here's a quick reference: https://payments.amazon.com/documentation/express/201728530#201747030 Any guidance will be appreciated.