question

Hi there, I followed the instruction from this link : https://developer.amazon.com/public/apis/earn/in-app-purchasing/docs-v2/verifying-receipts-in-iap-2.0#Setting up RVS to set up the RVS sandbox server. I got the "Receipt Verification Service Sandbox is up!" to show up as well as the example RVS sandbox to return the json response when entering it on the browser. However when I tried to httpRequest the same url using Parse SDK to the RVS sandbox server, it gives me 403 response error. So basically, I am not authorized to access that url. Any idea how to set it up so that Parse cloud code can make a httprequest to RVS sandbox server and come back with json response so we can test in app purchase on Amazon before we submit the build? Thanks for your help.