MV3 inject popup and enable/disable icon. Out of date docs?

[Nick Wehrhan]

Hi,

I am starting to develop a chrome extension and seem to have started at a fragmented time. I can't seem to get the docs to work with MV3.

I would like to
Show the pop up on a specific url and enable the icon

or 

Or inject a a popup into the page on a specific url and enable the icon

I keep getting errors with whats in the docs or its just not working:
https://developer.chrome.com/docs/extensions/reference/declarativeContent/#rules

I don't have a `page_action` in my MV3, just a `action`. I also noticed a function `chrome.declarativeContent.ShowAction()`  that I was trying to utilize. Whats the correct way to do this in MV3?