To be more concrete: security keys can communicate over USB or NFC. Just make sure it supports the protocol you want to use it for.

But there is also passkeys which is both software- and hardware based and is almost equally secure.

I am, specially after seeing how well it was implemented in the nightly version. It can’t be compared to an extension that enables the same capability.

Matrix, xmpp, IRC or even rocketchat are better alternatives.