Javascript event handling trace

I have a very specific need to identify the code that is attaching an event handler (specifically a Meta/Facebook tagging event) to an element. We want to have the developer team remove the code, but we want to specify exactly where it exists (so they can't say, Hmmmm i have no idea where that's being called from).

The person who solves this task will likely need to be extremely experienced in Javascript event handlers.

Hoping to do this via a screenshare.

We have an occasional need for this level of Javascript expertise so, if this works out, there will be occasional ongoing work, perhaps a few hours per month.