It should be that you use the sandbox account to request the official production link

const (
	appleSandboxURL    string = "https://sandbox.itunes.apple.com/verifyReceipt"
	appleProductionURL string = "https://buy.itunes.apple.com/verifyReceipt"
)

apple payment function

Need to insist on whether the requested link domain name is correct, the official production environment and the sandbox test environment