Debugging not working on iOS / Safari

I’m trying to debug my app on iOS, and not seeing any messages appear in Safari’s Web Inspector. I’m probably doing something wrong.

I’m running it on my iphone like this:

ionic cordova run ios --debug -l --address=

In Safari I think click Develop -> Iphone -> [My App Name]. Which launches the web inspector. But the web inspector shows nothing at all. No messages, no elements, nothing.

On the iPhone, in Settings -> Safari, “web inspector” is enabled.

I’m guessing I’m doing something wrong?