Custom gcode file location

Where does millmage saves the custom gcode configuration. I need to get on a text file to compare with vcarve postprocessor file to customize the millmage custom gcode for my machine

You have to select and export your Device:

It stores it in the preferences. @parsec is close - though that will export a bundle. It’s just a zip file… change the extension to .zip, extract the file and then look for the .mmdev file inside. That will have the device profile as a JSON file. But it will ONLY show gcode blocks that are different from the default. you are honestly better off just opening device settings and going to the Custom GCode tab, then scrolling through the blocks.