G code is a programming language used to control CNC (computer numerical control) machines, which are used to manufacture physical objects from digital designs. Here is a simple G code program that will generate a pyramid shape:

This program assumes that the machine is using absolute positioning (G90) and that the units are in inches (G94). It also assumes that the machine is using an XY plane (G17). The program begins by moving the tool to a safe starting position above the workpiece (G0 Z0.25). It then moves to the starting point of the pyramid (G0 X1 Y1) and begins the shape by moving down (G1 Z-0.1 F5). The shape is generated using linear interpolation (G1) and moves in a counterclockwise direction, returning to the starting point when finished. Finally, the tool is moved back to the safe starting position (G1 Z0.25).

This is just a simple example, and you can adjust the dimensions and shape of the pyramid by modifying the G code program. It is also worth noting that this program is specific to a particular machine and may not work on all CNC machines.