A developer is experiencing an issue with Alipay's asynchronous notifications to their Vercel-deployed API endpoint at https://my-domain.vercel.app/api/alipay/notify/.
Alipay's support team confirmed they're sending POST requests to the endpoint
They report receiving an HTTP status 0 error from the application
This appears to be a connection initialization error rather than an application-level error
The developer can successfully connect to the endpoint using Postman from their machine
No incoming requests from Alipay appear in their Vercel logs
Since it's an HTTP 0 error, they suspect the requests aren't reaching the application at all
Has anyone encountered similar issues with webhook integrations on Vercel?
Are there any Vercel-specific configurations needed for external services like Alipay?
How can they troubleshoot connection issues when no logs are being generated?
Any suggestions or guidance would be greatly appreciated.