Languages that don't have a Latin script

How can I display languages, such as Hindi, Arabic, Hebrew, Chinese, Japanese, Farsi, etc...?

When I try to add them, I just get white boxes on the screen.

 

Short answer is Yes.

When using TextMesh Pro <TMP>, the missing character glyph (the square) also known is .notdef glyph is displayed when the font asset and / or any of its potential fallback do not contain the requested character.

(1) Make sure you are using a source font file that contains the characters for the languages you are wanting to use.
(2) Make sure the font asset you are using contains those characters (if it is static) or is set to dynamic or has a dynamic fallback font asset using a source font file that contains those characters.

To find font files that contain character for various languages, check out Google Fonts which allows you to search for font files per language supported.

There are many other posts on the forum here where I describe how to work with the dynamic system and fallbacks, etc.

Also check out the Google NotoSans font family with its numerous font files with support for almost all languages.