How do I use the "imported fonts" options in WordPress's customize > fonts > choose font > "imported fonts" section?

Trying to find info about this, but apparently no one's mentioned this anywhere.

I want to use some local fonts (web compatible woff, eot, ttf, etc.), hence the question.

Can someone throw some light on this?

Thanks

P.S. Have trued using some plugins, but do not seem to work well with WP.