Auto Checkout / Purchasing APIs Endpoints For Mobile Bot

I currently have an Android and iOS app that automates the buying and checking out of products from websites. We currently use custom unofficial APIs and endpoints to do this. The app supports Walmart, Target, Topps and Panini. What I need from you? I’m looking for a backend developer who can create this checkout process via Endpoints and APIs. You will have to develop this for Specific websites and maintain the APIs. I prefer this to be placed on a server and then the app will send request to the server. This way we can update without needing to update the app. Here’s an example of the check out process. 1) logins into the user account 2) finds the product from the url or the product pid 3) adds quanity and then the product to cart 4) retrieves the billing and shipping from within the application 5) sends the billing and shipping information 6) sends the payment information 7) submits order Please do not apply if you do not understand what I am hiring for.