There are multiple reports about the Bitwarden browser add-on not working in Firefox, and I have the same problem.
I am using the most recent Firefox version 145.0.2 and a fairly recent Windows 11 Pro 25H2. When I try to log into a website with a passkey that is already stored in my Bitward account, the Bitwarden popup window does not open, there is no way to select my passkey, and therefore I cannot login.