I got something similar to this: https://www.amazon.com/gp/aw/d/B099S8CV5Y/ref=sspa_mw_detail_6

I put a cardboard ramp scratch board thing in one half, the litter box in the other, and it perfectly fit together so the box couldn't slide and all litter he kicks stays inside where it can easily be taken outside and emptied like once a week.