How to import fonts into Scrivener 3?

I need fonts that are not in Scrivener3.
How can I import them?
Thank you who will say it …
and sorry for this bad english,

Scrivener uses system fonts. Install the font you want on your system and it should be available.
You might have to restart Scrivener if you install a font and it is not immediately available.
If you want to use a font without installing it on your system, I have no idea how to do this.

Thank you very much.