Access Shockwave Flash COM Object using WebBrowser Control

Question

I have an HTML page that contains the flash game Club Penguin. I'm trying to make a Desktop client for my website that allows the user to get and set flash variables. How can I access the Flash COM Object using a WebBrowser Control?

Here's what I have tried so far:

object o = webBrowser1.Document.InvokeScript("return document['cp_flash']");
ShockwaveFlash flash = (ShockwaveFlash)o;
Console.WriteLine(flash.FlashVars);

I expected to get FlashVars logged to the console, but instead got a NullReferenceException on line 3.

What am I doing wrong? Is this even possible in 2019?