There are several things you can try to encourage your cat to use the litter box:

1. Keep the litter box clean: Cats are clean animals and they may be less likely to use a dirty litter box. Scoop solid waste out of the box at least once a day, and completely empty and clean the box once a week.
2. Make the litter box accessible: Place the litter box in an area that is easily accessible to your cat. If your cat is elderly or has mobility issues, you may need to provide a litter box on every floor of your home.
3. Use the right type of litter: Some cats prefer a certain type of litter, such as clumping or non-clumping. Experiment with different types of litter to see which one your cat prefers.
4. Don’t punish your cat: If your cat has an accident outside the litter box, it’s important not to punish them. This can cause your cat to become scared or anxious, which can lead to more litter box issues. Instead, try to determine the cause of the behavior and address it.
5. Provide enough litter boxes: It’s a good idea to have at least one litter box per cat in your household. If you have a multi-level home, it’s a good idea to have a litter box on each floor.

I hope these tips help! Let me know if you have any other questions.