User Profile

Hi!I'm trying to get Apple Pay Payment session following by this instructionhttps://developer.apple.com/documentation/apple_pay_on_the_web/apple_pay_js_api/requesting_an_apple_pay_payment_session1. At the first step I'm getting validation URL using Javascript API. It seems everything is fine at this step because I can receive "validation URL".2. Next I'm sending server side query to this "validation URL". But this query gets failed every time. It's always the same error: {"statusMessage": "Payment Services Exception Request timed out","statusCode": "504"}This is the data I'm trying to send{"merchantIdentifier":"merchant.com.my-store","displayName":"My Store","initiative":"web","initiativeContext":"my-store.com"}I'm also using valid Merchant Identity certificate to sign this request. I know this because without a valid certificate I'm getting another type of error:error:14094410:SSL routines:SSL3_READ_BYTES:sslv3 alert handshake failureSo it seems I have no problem with transport layer because I can receive a valid JSON as a response.But please tell me why Apple server is always respond with 504 (Request timeout) error?Am I doing something wrong?