Reddit mentions of Pet Time Dog Toilet Pet Dog Puppy Cat mesh Potty Litter Training pad Holder 21" X 17" AMT-40 (Pink)

He has un-learned that it's nice to be clean. He needs to re-turn it, so you need to change your set up.

I always tell people to buy the tall Iris pet pen.Then get a mesh potty pad or fake grass pet potty - personal preference here, you just have to get something where they can't get to and shred the pad.

Put the crate in the back of the pen - start without bedding - and then put the potty thing right in front of it. Now we've created two clear zones - a comfy sleeping zone and a pee zone. By sleeping and peeing on both surfaces, their stupid little brain eventually is like "I can pee somewhere other than where I sleep. Huh. It's kind of nice not to sleep in my pee." They sometimes start to sleep on the potty thing, but don't worry about it, it's still part of the process. Eventually, when they seem to have the idea, try introducing a little bit of bedding back in and BE CRAZY ABOUT WASHING IT. If there is a drop of pee on the bed you can backslide. So wash wash wash so it stays clean and fresh (towels or sheets are a good/cheap way to start). Over time, you can introduce good bedding.

Remember, IGs have bladders the size of acorns, so they have to pee all the time, basically. A lot of people have success with the pen set up forever, and others can take them out enough to phase back into crates.

But right now, you need to give them the opportunity to re-learn how nice it is to be clean.

A side note, buying a dog from a good breeder who potty trains them - or at least you are 100% sure they're not raised to pee where they sleep - goes a long, long, long way in this.