For all Windows Users: There is a script that enables this extension to work on Windows with Firefox. Search for "icloud-passwords-firefox by au2001" (click on the github link)

On Mac: It worked okay. But after i Installed macOS Sequoia 15.4 it prompts me with "This extension requires macOS Sonoma or later" Please fix this since i am on the newest full release version of MacOS (not beta)