How do I know the data is empty on Trustpilot Embeded?

Question

I'm following this instruction to embed the Trustpilot on my website. It will render a tag that contains the data. I would like to check when the data is empty like this:

I found that the Trustpilot will create an object like this window.Trustpilot.Modules.WidgetManagement but still don't know how to detect that the data is empty or not.