"No, we do not want to see the car."
Translation:Nac ydyn, dyn ni ddim eisiau gweld y car.
This is explained in the 'Hints and Tips' for the 'Wanting' section.
The dictionary word is eisiau, but it is very often pronounced as /isha/, /isho/ or /ishe/ depending on where in Wales you are. Some people, especially in NW Wales, like to spell it as they pronounce it, so the course allows isio as well.
Unless you have a reason to spell it isio, stick with eisiau.