The KDE 6 announcement says that
On prior versions you chose between either password or fingerprint authentication for the lockscreen. In Plasma 6, both are supported at the same time.
I’ve updated my Neon install, what do I need to do to enable this? I’ve set up a fingerprint through the user settings, but when the screen is locked I still have to use my password to unlock - there isn’t a prompt, and touching the reader doesn’t seem to do anything
Empty password doesn’t prompt for a fingerprint, and I thought that was the old hacky workaround for Plasma 5 that Plasma 6 was supposed to have fixed?
Even if it is, I’m unable to find any other solution. It’s at least worth a shot.
Do be sure to report this bug in the meantime, it’s likely related to pam &/or SDDM.