By default, the G02/03 commands make arcs on the XY plane. If you want to do them in another orientation, you'd need to give a G17,G18, or G19 command. Here's an explanation: https://infosys.beckhoff.com/english...g02g03.htm&id=
I'm not sure what you're trying to do, but Inkscape is a 2D program, and any G-code it makes will be limited to 2.5D at best. To take advantage of your 4-axis machine, you might want to look into 3D CAD CAM software.