I have apple web payment integrated on website, and it work fine when i test it using real cards. I wanted to test it using apple TEST cards, so i invited SANDBOX test user from here https://appstoreconnect.apple.com/access/users/sandbox and logged in to test device using this test id. but it fails to start a merchant session.
System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: Authentication failed because the remote party has closed the transport stream. at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult) at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar) --- End of inner exception stack trace --- at System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult, TransportContext& context) at System.Net.Http.HttpClientHandler.GetRequestStreamCallback(IAsyncResult ar) --- End of inner exception stack trace --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Net.Http.HttpClient.<FinishSendAsyncBuffered>d__58.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult() at Gateway.MobileWallet.Domain.ApplePay.Clients.RequestPaymentSession.ApplePayPaymentSessionClient.<RequestMerchantSessionAsync>d__3.MoveNext() in