Check your Blender Prefereces first: [Edit] > [Prefereces...] > [File Paths] > [Fonts]

The typical font path is as follows.

In Windows:

C:\Windows\Fonts\

In Ubuntu Linux:

/usr/share/fonts/

You can also set an additional font directory if needed (use v1.2.0 or later):

[Edit] > [Preferences...] > [Add-ons] > [Image Editor+ Text Tool] > [Additional Font Directory]

You can now use a multi-line text source (use v1.2.0 or later).

TTF (TrueType Font) is supported. These font files typically use the ".ttf" extension.

However, some symbol fonts (wingdings, dingbats, etc.) may not work.