generate_typography_default_fonts

The generate_typography_default_fonts filter allows you to add font families to the system/default list in the Customizer.
Usage
Please refer to the Using Filters article to learn how to use this filter.
Example
add_filter( 'generate_typography_default_fonts','tu_add_system_fonts' );
function tu_add_system_fonts( $fonts ) {
$fonts[] = 'My Font Name';
return $fonts;
}