“hammer-code” @keyre124 Pointed out that you can find out through CoreGui, that’s the way I found out.
Edit
Tried to find it by getting the font with selection service and this is what I got.
Someone might find it useful.
19:39:02.679 > local selection = game:GetService("Selection") print(selection:Get()[1].FontFace) - Studio
19:39:02.680 Font { Family = rbxasset://LuaPackages/Packages/_Index/BuilderIcons/BuilderIcons/BuilderIcons.json, Weight = Bold, Style = Normal } - Client