Unless your rabbit is a larger breed, the best litterboxes for rabbits have an entry cutout, such as this one sold in the BinkyBunny store:
https://store.binkybunny.com/collections/supplies/products/litter-box-easy-entry
Although we don’t have this particular brand of litterbox, we have two that are virtually idential in design, which were previously sold by Purina for small dogs under the “Second Nature” brand (to the best of my knowledge these are no longer sold, perhaps because using a litterbox is not second nature for dogs!).
If you have a larger breed such as a Flemish giant, checkered giant, or French lop, the best litterbox is definitely a large, low underbed storage container.
https://www.sterilite.com/product-page.html?product=19608006&mid=257
Personally, I avoid cat-style litterboxes for rabbits when possible: I know that leaping hurdles is easier for them than it is for us, but I’d hate to do it when I have to go!