Great extension, works perfectly for me

Look in your address box for the icon. If there is a feed, you'll see it. If not showing, then there is no feed. Simple. Popup under it is also clean looking and simple but effective. Good tool. I use it to grab feed url for QuiteRSS on Linux Mint Mate 20. All good.

Looks great. A few lines of the actual feed (if available), similar to Firefox's old integrated reader, would be nice.

Simple, useful and light.
One suggestion, the tab icon is hard to see in a dark theme like mine:
https://addons.mozilla.org/en-US/firefox/addon/solarize-fox/
Please use the same gray of URL icon.
Thanks.