Walmart Marketplace API Inventory Update VB.NET

I am working on a Walmart API integration. I need assistance with the inventory update process. I have made some attempts using the sample code on ChilKat site but without success. This project must be completed using VB.NET (2015 or 2022) and target a 4.6 .NET framework. There are two examples on Walmart’s site, one using XML and one using JSON. Either format is acceptable. Experience working with Walmart API’s a huge plus so make sure to mention that when responding. I have sandbox and production credentials available for this project. The deliverable will be a simple product update process that updates Walmart inventory using a file sent from a VB.NET desktop application that can run on a Windows platform. Since this is a fairly simple project, Milestones will include a down payment and a completion payment.