Prevent a Flutter webapp to be embedded on iFrame

Is there a way to prevent/detect any website to embed the flutter webapp I've published to a domain?

I created a project on Firebase and hosted a Flutter webapp in it: https://friendlyeats-flutter-codelab.firebaseapp.com/#/.

I noticed that if I add the url in an iFrame, the webapp shows inside that iFrame in any website. Is there a way to prevent this?

I tried using Uri.base.host, Uri.base.origin and Uri.base.authority (by displaying a message on screen with these values in order to see if I can detect the host that's embedding the webapp) but they all show friendlyeats-flutter-codelab.firebaseapp.com as a value, even if I'm embedding the webapp in an iFrame in a different domain (i.e. some-website.com).

May there be some way to detect the iFrame host using Dart/Flutter?

EDIT:

I've also tried the following with the same results

html.window?.location?.host
html.window?.location?.href
html.window?.location?.origin
html.window?.origin
html.window?.document?.origin //null
html.window?.document?.domain
html.window?.document?.baseUri
html.window?.document?.suborigin //null
html.window?.document?.window?.location
html.window?.document?.parent?.namespaceUri //null

Add the next import to the class:

import 'dart:html' as html;

Then you can access the host url by calling html.document.referrer. If it returns empty then the website is not being embedded. If it returns a value (which might not necessary be the main website url - i.e. for a Google Sites it returns https://www.gstatic.com/ instead of some-website.com) then you can show a different error screen or whatever you want.