The main Path wiki documentation page: Path Workbench links to: Project Commands - Creates a new CNC job., which leads to: Path Job - Output, which in turn leads to: Path Post
In bold at top of page:
Each CNC Controller speaks a specific G-Code dialect, requiring a Dialect-correct Postprocessor to translate the final output from the agnostic internal FreeCAD G-Code dialect.
The Options section has a large discussion on common options.
For specific options for your chosen Postprocessor, just hover mouse cursor over the "Arguments" input field.
Here's the place for discussion related to CAM/CNC and the development of the Path module.