We’re currently trying to implement Apple Pay on our checkout flow pages, which are part of a NextJS application. Due to the fact that our checkout flow is a React-based application, we’re not using the <apple-pay-button> element, but a custom button. We are using the Apple Pay JS API. It seems like we are getting most of the pieces in place, however we’re not having any success with the session.onvalidatemerchant event. Currently when a user clicks the Apple Pay button, the Apple Pay dialog appears briefly with a ‘Payment not completed.’ message and then closes immediately. Given the nature of the issue it seems like it could possibly be a configuration error, but we’re not really sure how to check that everything is configured as it should be. Some questions that we have at the current moment: What version of the Apple Pay API should we be using? Should the domainName value that we’re passing to Apple contain https:// ? Should we be calling the https://apple-pay-gateway.apple.com/paymentservices/paymentSession endpoint directly from our front-end code? Should we pass data to session.completeMerchantValidation(sessionData); as a JavaScript object or JSON?