Flutter - App Store Connect rejection due to needing "functional link to the Terms of Use (EULA)" in "your app's binary"

Our flutter app, with a subscription membership in-app-purchase, is repeatedly being rejected by App Store Connect for the following reason :

Specifically, we were unable to find the following required information in your app's binary:

– A functional link to the Terms of Use (EULA)

How do we update the app's binary to have a link to the EULA ?
Does anyone know what this message actually means ?

Note that we do show the EULA when the user first enters the app, and there is link to it - so this message doesn't appear to be about the actual functioning/UI in the app.

Note that this is a Flutter app, so bonus points on the answer if you can tell how to set the EULA in the binary in Flutter. ("bonus points" being an expression, I have no authority from SO to allocate extra points)

Solution

As far as I know, they need a button that opens the browser on a public page that contains your Terms of Use/Privacy Policy. This button should be available at all times, not only when the user first opens the app.

You can do that using the url_launcher package. Example:

ElevatedButton(
  onPressed: () {
    launch('https://policies.google.com/terms?hl=en-US');
  },
  child: Text('Terms of Use'),
),

I have implemented this a few times and haven't had issues publishing to the App Store.