Why the URL to the app UI is not local IP when tunneling?

Forge
1

Hi,
When tunneling, why the URL to the app UI is not local IP?
This page says “Tunneling runs your app code locally on your machine”, so I wonder why I need to use our site URL, not local machine IP to access my app UI from browser.
https://developer.atlassian.com/platform/forge/tunneling

2

I don’t think I understand the question. Are you trying to see just the rendered HTML of your custom UI app in the browser or to run the app in the product?