Ender-3 v2 UI Customization

How do we customize the UI of the Ender-3 v2?
For example, on the firmware by Smith3D we can see that they have added new menu items. How do we do that?

You would have to edit the Marlin source code, recompile, and then load onto the printer. Since it’s Marlin 2.x, you’ll need to use VS Code with the PlatformIO & Marlin Auto Build extension.

Yes I’m already using VS Code to update the firmware. But concerning the UI, I don’t know which files specifically to modify.

From what I’ve seen, most changes are made in configuration.h, with some being made in configuration-adv.h. In VS Code, near the top left, you will find a search box. Searching for something there will search all the files. I would search for “menu”.