How to litter train 8 week old Female rabbit.?

I have a long rectangle size rabbit cage (top half metal bottom half plastic) on wheels low to the ground. I just got my 8 week old bunny last wednesday. The litter box is a triangle with grate that sits above the litter with a guard that snaps into place (So she does not lay in the mess) and the unit hangs in the corner on the wall of the cage so she can not move it around. I have the food and water on each side as I know the food and water go right through her. She chooses to urinate on the two long sides of the cage. 2-3 times a day I clean her cage and use Natures Miracle to remove the mess and get the odor out. She leaves some pellets in the litter box but the rest she leaves along all other adjacent sides of the cage. What are my options, I thought of just filling her entire cage with the litter bedding (Care Fresh) however she tries to eat it so that is no longer an option. I tried leaving a soaked urinated tissue in the litter box to associate the smell to the litter box hoping she would go. I never scold her because she does not know better and it would do nothing if I did.Please advise as I am persistent and open to suggestions.