XD should load all fonts you have installed on your OS. If you just installed a new font then please restart XD in order to have access to them. Here's a link to how you can install fonts using Font Book: Mac Basics: Font Book - Apple Support
Hope that helps
What about to create a gradient?
This works great when I'm viewing the project on my desktop but when I sync it to view on my iPhone, the fonts are missing. I'm using the Google font Barlow which is not in Typekit. Am I doing something wrong or am I forced to use only fonts available in Typekit?