Going from 2 layer to a 4 layer

How do you change to a 4 layer board from a 2 layer in 5.1.4. What I see on the net and the forums has you use Setup but that no longer exists and Board Setup doesn’t seem to show me anything related to layer count. I’m using the Mac version.

file -> board setup should have a dropdown for layers

Ah, there you go. Thanks.