An IT company is creating an online booking system for hotels. The booking workflow that the company has implemented can take over 3 hours to complete as a manual verification step is required by a 3rd party provider to ensure big transactions are not fraudulent. As a DevOps Engineer, you need to expose this as a secure API for the end customers. The website must be able to sustain 5000 requests at the same time. How should you implement this in the simplest possible way?