Google has upgraded the rich results test to show embedded resources. It is beta but it can show external elements included by a page. Here is an example of a page here but you can run it on any page.
Here is Google's announcement with a screen shot:
New in the Rich Results Test! 📣 The tool now reports unloadable embedded resources, such as external elements included by a page.
— Google Webmasters (@googlewmc) January 13, 2020
👩💻 try it out at https://t.co/AGp8xwSsDK
📖 learn more at https://t.co/stGphCujZN pic.twitter.com/3HU0aOOvh6
This can help you do more debugging of issues with search or even your site.
Forum discussion at Twitter.
