Help adding signal tag for agency to embedded website iFrame

Greetings!

I’m hoping a genius on here might be able to help me out. I need to add a signal tag from an ad agency to a button on an embedded site iFrame holding a 3 party newsletter widget for RIO tracking. Possible in wix code? How? If not, if I switch to the self styled HTML code for the widget can I just tack the signal code on in the iFrame. Thank you for any advice.

You might be able to use an HtmlComponent (it depends on the embedded code). See the article Working with the HTML Element in Wix Code for details.