Can’t find the list of supported browsers. Where did you read that ? Have not tried it but maybe it will not work with Librewolf flatpak, but in Arch Linux you can install the Librewolf binary with AUR. There are several other add-ons https://aur.archlinux.org/packages?O=0&K=librewolf
The problem is that KeePassXC needs to specifically allow types of browsers to connect to its database, and while Firefox and all other usual suspects are there, Librewolf isn’t and so the add-on can’t connect to KeePassXC.
Can’t find the list of supported browsers. Where did you read that ? Have not tried it but maybe it will not work with Librewolf flatpak, but in Arch Linux you can install the Librewolf binary with AUR. There are several other add-ons https://aur.archlinux.org/packages?O=0&K=librewolf
The problem is that KeePassXC needs to specifically allow types of browsers to connect to its database, and while Firefox and all other usual suspects are there, Librewolf isn’t and so the add-on can’t connect to KeePassXC.