Developer Needed to Diagnose Online Checkout / Payment Processing Error

Web Developer Needed to Diagnose Checkout / Payment Processing Error Using Browser DevTools / Network Analysis” I am looking for an experienced web developer or payment/API specialist to help diagnose a recurring checkout error I experience when purchasing tickets through Paciolan/eVenue college ticketing websites. I am not looking to automate purchases, bypass website security, or modify the website. I only want to diagnose why a normal manual checkout attempt is failing. The Problem I can: Log into the ticketing website normally Select tickets Add them to my cart Enter billing and payment information However, when I submit the order, the website returns a generic processing error and the purchase does not complete. There are several possible causes, including: Credit card/payment authorization Billing address or AVS verification Browser/session/cookies Account-related issues Network/IP-related issues Website/API errors Payment gateway or fraud/risk screening I would like someone who can help determine where in the checkout process the transaction is failing and, if possible, identify the specific error being returned. What I Need I would like to screen-share while I perform a normal checkout attempt. You should be comfortable using tools such as: Chrome Developer Tools Browser DevTools Network Analysis Network tab Console XHR/fetch requests HTTP request/response analysis HAR files API debugging Payment gateway troubleshooting The goal is to inspect what happens when the order is submitted and determine whether the failure appears to occur: In the browser/client During an API request At the ticketing platform During payment processing During address/payment verification At another identifiable point in the checkout flow If the browser receives an error code, HTTP status, API response, payment response, or other diagnostic information that isn't displayed to the customer, I would like that identified and explained. Ideal Experience Experience with any of the following would be especially useful: E-commerce checkout debugging Payment gateway integrations Payment processing APIs REST APIs Chrome DevTools HAR/network-log analysis JavaScript debugging Stripe, Adyen, Braintree, Authorize.net, CyberSource, Worldpay, or similar payment systems Experience specifically with Paciolan/eVenue would be excellent but is not required. This is primarily a diagnostic/troubleshooting project, not a programming or website-development project. When responding, please briefly explain your experience diagnosing checkout/payment failures and whether you are comfortable analyzing browser Network/DevTools activity during a live screen-share session.