ANZ Payment Gateway Error Resolution

I'm looking for an experienced developer to resolve an integration error with the ANZ payment gateway on my WordPress website. The issue arises during the checkout process, resulting in a "System error" message being displayed. There are no additional plugins installed that might affect the checkout process. Key Requirements: - Expertise in payment gateway integration, particularly with ANZ - Strong problem-solving skills to diagnose and fix integration errors - Experience with website checkout processes and error handling - Ability to communicate progress and provide a solution in a timely manner Ideal Skills and Experience: - Background in web development, especially with WordPress - Familiarity with relevant APIs and security protocols - Previous experience with similar projects involving payment gateways Please provide a detailed approach to fixing this issue and any relevant experience. I have attached a video for reference to help you understand the problem better. Payment page link https://www.adssolar.com.au/payment-paynow/