Hi mmerlinn

The Lighthouse extension you mentioned in your question, do you mean this? https://addons.mozilla.org/en-US/firefox/addon/google-lighthouse/?utm_source=addons.mozilla.org&utm_medium=referral&utm_content=search

If yes, there will be an icon on the top bar beside the menu after you install from the link

Hi Merlinn, Lighthouse has theme and extension. I am assuming that you are using Google Lighthouse extension. I installed the extension. It is showing the extension icon on the toolbar. try installing the extension again https://support.mozilla.org/en-US/kb/find-and-install-add-ons-add-features-to-firefox in case you extension installed in your Firefox but you cant find it in toolbar. right click on toolbar and select customize and drag & drop to customize https://support.mozilla.org/en-US/kb/customize-firefox-controls-buttons-and-toolbars

Do not know why the icon was missing the first time, but I can now use Lighthouse, though I had to do some experimenting to make it work since I did not find any documentation stating that it works only on an active browser page.