We have an App in the App store and lately we've been having a lot of errors with the endpoints. We're making a WebClient request (C#) to the App store /verifyReceipt endpoint with receipt-data field. All of the documentation I'm finding is for XCode and C++/Swift.
When I make a post or a Get to https://buy.itunes.apple.com/verifyreceipt I get a 404 from Postman, which should mean the endpoint doesn't exist, but I'm concerned that it's telling me that my receipt doesn't exist (since I'm not passing it valid receipt data, just trying to check the health of the endpoint). When I try the same endpoint in the Sandbox I get a 503 Service Unavailable.
I'm new-ish to this company and incredibly new to dealing with the App Store. The documentation is extensive and seems to give little context for me to easily pick it up without completely rebuilding the API. Could someone direct me to a resource that might help? And yes I've googled, but haven't found anything specifically pertaining to their REST API.
Additionally if you know something about the REST API and if they closed down the service or something could you please direct me to information about that?