sddm

https://wiki.archlinux.org/title/SDDM#[Using_a_fingerprint_reader](https://wiki.archlinux.org/title/SDDM#Using_a_fingerprint_reader)

others like sudo,su

Add this to /etc/pam.d/{su,sudo}

 auth required pam_env.so
 auth sufficient pam_fprintd.so
 auth sufficient pam_unix.so try_first_pass likeauth nullok
 auth required pam_deny.so