Docs Bug? Proxy set in Env var

Created by: eddiemonge

This section says the proxy can be set with an env variable but I don't see how in the code. I think this was removed at some point. Can someone confirm that is true? If so, then the docs need to remove:

Use environment variables to inject the right server host and port into your app.

If this is still possible, can someone add documentation on what the option is?