What is the default font on Julia Plot (and how do I see what font is being used?)

What is the default font on Julia Plot (and how do I see what font is being used?)

default(:fontfamily)

Hello.If I want to see what font can be used,what should I do?

using Plots
default(fontfamily="Arial")

But it did not work.Thanks

This will depend on the backend. For GR (the default), these exist: Fonts — GR Framework 0.66.0 documentation

Many thanks