Wikipedia says:
Also referred to as WPA-PSK (pre-shared key) mode, this is designed for home and small office networks and doesn't require an authentication server.[9] Each wireless network device encrypts the network traffic using a 256 bit key. This key may be entered either as a string of 64 hexadecimal digits, or as a passphrase of 8 to 63 printable ASCII characters.
Is it true that every human in the world uses ASCII printable characters for their WPA passwords? What about China, Arabic countries, Japan and many many other?
Latin alphabet uses only small fraction of world's population. Are people forced to set up ASCII printable character for their WiFi password on the entire world?
Yes, it is correct. We can also use the alphabet as well as their native language characters.
It is necessary other than WiFi password.
For example, even a URL or e-mail address is composed of the alphabet.
However, please do not worry. This is easy thing.
Alphabet has been printed on the keyboard, in any country.