1) Use a scoop to add litter https://www.amazon.com/gp/product/B004LOEKS4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I cut my kitty litter box 3/4 around with a utility knife (box cutter) and scoop out. It takes 8 scoops with this to fill after a dump (7 if you fill the scoop all the way). I top off with half a scoop every day.
2) Trash bags. I use these (cheap and work very well): https://www.amazon.com/gp/product/B00S7NN770/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
3) Buy a couple cans of compressed air and give a quick spray at the sensors every few days. The compressed air could trigger the sensor briefly because of the condensation, but it keeps mine clear.
4) Buy a good step to cover the robot step for $34 https://www.amazon.com/dp/B09BBTZCKS?psc=1&ref=ppx_yo2ov_dt_b_product_details
5) If your cats have a tendency to pee out the front (they face in instead of out when going)
a) put about an inch or two of pee pad or plastic (like a cut up gallon size ziplock bag) into the robot then snap the fence down on it. This extra bit will stop the pee from going between the rotating globe and the outer shell (which stops pools of pee collecting inside the robot above the drawer)
b) put some more pee pad around the steps, on the steps, and on the floor. At least until they stop peeing for distance outside the robot.
c) I used 2 paint stirring sticks from home depot (they give them free) to make a cross, a couple rubber feet from home depot https://www.homedepot.com/p/Shepherd-7-8-in-Off-White-Rubber-Screw-On-Furniture-Bumpers-for-Chairs-and-Table-Floor-Protection-4-Pack-9131/100148565, and some dollar store mardi gras beads to make a good "curtain" to hang in front of the entrance to swing and tap them on the butt. "Usually", makes them turn around and pee like they should.
I use a scoop https://www.amazon.com/gp/product/B004LOEKS4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I cut my kitty litter box 3/4 around with a utility knife (box cutter) and scoop out. It takes 8 scoops with this to fill after a dump. I top off with half a scoop every day.