What tool is needed to import gcode

Hi, trying to use halftoner to create halftone images. I can export gcode from it, but on importing to easel getting a prompt to use supported gcode application to prep the file, can anyone clarify this step?

Usually I use a post processor to export my jobs from Cad-Cam program, most Cad-Cam programs let you define the post Processor.

Each CC program seems to use a slightly different PP file

try this link for some help

Post Processor