Using Fingerprint Authentication on ThinkPad X1 Carbon + Artix Linux

Hello, I'm incompetent.
My ThinkPad X1 Carbon has a fingerprint reader.
However, personally, I've disliked fingerprint authentication on PCs until now, so I haven't used it. But now I've started to think, "Isn't it a good thing after all?" so I'll use it.

First, install the following:

sudo pacman -S fprintd  

Adding a fingerprint. It seems you shouldn't do this with sudo. I saw somewhere on GitHub that there's a bug.

fprintd-enroll  

Then, in the configuration file, we'll make sure to load the fingerprint authentication library.

sudo vim /etc/pam.d/system-auth  

**alleycat**:[**haturatu**]:~**$** cat /etc/pam.d/system-auth    
#%PAM-1.0  
  
auth       required                    pam_faillock.so      preauth    
# Optionally use requisite above if you do not want to prompt for the password    
# on locked accounts.    
**auth       sufficient pam_fprintd.so**    
**auth       [success=1 default=bad]     pam_unix.so          try_first_pass nullok**    
auth       [default=die]               pam_faillock.so      authfail    
auth       optional                    pam_permit.so    
auth       required                    pam_env.so    
auth       required                    pam_faillock.so      authsucc  

The bolded parts are what I added.
Apparently, if you write it above try_first_pass nullok, it will load the fingerprint authentication module first, but if you write it below, it becomes a two-step authentication where you're asked for fingerprint authentication after entering your password.

So, with just this, authentication when using sudo is completed, which is easy.

However, after registering this, it said "index finger", but can it tell which finger it is just by registering...!?
Or is it assumed to be the index finger?

That's all for now.

See you next time.