#commentz
$  #non-root console
#   # root console

# useradd -m anek
# #passwd -l anek    #lock (disable) password, not needed because no password by default

# sudo -u anek -s
anek$ ssh-keygen -t ed25519ssh-keygen -t ed25519
Generating public/private ed25519 key pair.
Enter file in which to save the key (/home/anek/.ssh/id_ed25519):
Created directory '/home/anek/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/anek/.ssh/id_ed25519.
Your public key has been saved in /home/anek/.ssh/id_ed25519.pub.
The key fingerprint is:
SHA256:bbfVs8lfktz7yFI2fIPcaxO9v6xmnnAjXDFFU0ogvn4 anek@anek-G31M-ES2L
The key's randomart image is:
+--[ED25519 256]--+
|          . ..o+o|
|         . . ....|
|          .  o.  |
|         . .  o. |
|        S + oo+.o|
anek$ cp .ssh/id_ed25519.pub .ssh/authorized_keys
mail .ssh/id_ed25519 or scp it via ssh