How can I kill this notification through Task Manager?

I regularly get notifications like the one in the lower-right below for new uploads to Youtube channels I subscribe to. For some reason, this one would not close after clicking the close button or the X in the upper-right corner of the window. I assumed it would appear under Apps on the Processes tab in Task Manager, where I could "End" it, but no dice; I had to restart my system. If it happens again, I assume it will show up somewhere in Task Manager. Where should I look for it, and what will it probably look like? Thanks for any tips.

It's a web notification via Google Chrome, as indicated on the top line.

So it may be possible to dismiss it by clearing notifications in the Action Center.