The doc states that debug output will also appear in Web Server tab, but this is not the case. How to enable it?
You'll find the Debug option in the Server Connect settings @Quy
This is Target specific so you will have to enable it for your selected Target (which should only ever be your local development environment).
NEVER enable Debug on a production environment as sensitive information may be shared inadvertently. Once you finished debugging is always good practice to just double check you are not publishing with debug enabled. Then check again, and again.
Sorry I forgot to mention that Debug option is enabled and on Local Development. It is still a no go.