In general, these are the batteries (site-specific): https://github.com/getAlby/lightning-browser-extension/tree/master/src/extension/content-script/batteries
Apart from that, for any site in general, if it has a meta tag in it's head tag like this:
<meta name="lightning" content="[email protected]">
<meta name="lightning" content="lnurlp:[email protected]"> the extension will pick it up and will turn the icon blue