Assuming your input image is proper 360x180 Spherical/Equirectangular you only need to adjust the width as the height will auto change because the aspect ratio stays the same 2:1
If you have a partial panorama, even a 360° Cylindrical panorama you will need to check what "type" the panorama image is being classed by Panoweaver and adjust if it got it wrong.
Regards, Smooth