How to get an app URL?

I need to add to the list of allowed URLs from which http requests can be received. How do I figure out which URL my app has in AppGyver?

Once built, standalone apps should be generating requests as localhost, which won’t help.

Web app and preview run through the related URLs.

Your best bet is to not focus on where it’s coming from, but instead focus on passing something like an authentication key, checking request variables for legitimacy, etc. This is how public APIs work and if you’re building an endpoint, just mimic their behavior.