You go to the world map and select Earth Shine, to the spot where you get to choose the 3 options (Explore, Exit, etc), and then hit play on the macro. Also make sure to set the delay as needed if you want to stay Lapis-netural.
Also this thread here has a larger selection of macros:
https://www.reddit.com/r/FFBraveExvius/comments/55f44k/lets_talk_nox_macros/. The thread says Nox but it the same ones for MEmu, and there's a section on how to install them as well.
For example he has one that selects individual enemies to build and use LB, useful for Cecil if you have him.