How to fill areas in an SVG drawing

I'm working on a drawing mode for my CNC 3018 using a marker. I've managed to convert my drawing into GCode, but I'm running into an issue with filling areas. My SVG has filled regions, but when I convert it to GCode using this SVG to GCode generator, those areas aren't being filled.
Is that normal? Does the software not support filled areas, or did I do something wrong?

Thanks !
