Cats won't use new covered litter box
My cats have been using a litter box for 10+ years. I got a new covered one and now one or both are peeing on the floor just outside the box opening!
I'm sorry to hear your cats are having a problem with the new box. A few key points...
1. Cats hate change, and it's best to make these changes slowly, using the same litter your cats have always liked.
2. Cats love choice, so it's best to add a new litter box, rather than replacing the old with the new right away.
This gives the cats the choice to use whichever box they want. Once the cats are using the new box on a regular basis, you can typically remove the old one.
3. Some cats hate covered litter boxes, or at the very least, have a hard time getting used to them. I've given up on using covered litter boxes as it doesn't seem to serve the cats.
If you were previously using an uncovered box, the covered box may seem foreign to the cats.
If you're going to use a covered litter box going forward, you might try leaving the cover off when first getting the kitties used to the new box.
With the old box and the new box side-by-side, both uncovered, your cats can make their own decisions about which box to use. They can get used to using the new box without being disturbed by the cover, and without being forced into a situation where they don't feel comfortable.
Then you can try adding the cover later, once they've accepted this new box. When you're sure everything is working well, you can get rid of the old box. Baby steps.
Assuming there's no medical condition causing your cats to urinate outside the box, I'd say it might be helpful to back up a step. Perhaps you can try the above suggestions and let us know how it goes.