i had a rat (as a pet lmao) and what we did for the cage was buy a large pot and put it underneath, that way all the stuff would go into that pot. (yes you still gotta clean it but its way better).
if you wanna upgrade the cage buy something to put underneath it, remove the floor (if it has some floor that doesnt let things go thru), you can make a hole in the cage too where the bunny poops and pees.
u gotta clean the pot everyday but bunny fren will be happi <3