Hi @swasteer ,
The 502 error you’re seeing is being generated by the server at your targetUrl. The Asana webhook system is trying to establish the webhook “handshake” to verify your server, and your server is returning a 502. This could be when it sending a POST to send the X-Hook-Secret header to establish the secret to use, or sending the initial X-Hook-Signature header. In either case, Asana is expecting a 200 response from your server and it is receiving a 502 instead.
I recommend using Postman to test sending messages to your ngrok endpoint and seeing what your server is returning.
Hope this helps!