Stackable 36 Inch Dog Crate with Lockable Wheels, Top Access, Heavy Duty Indestructible Escape Proof Dog Crate Cage Kennel Indoor with Removable Tray & Metal Grids for High Anxiety Medium/Small Dogs

I got this one when I was moving (to keep cats in, in the car). If you can't find a good one, I highly recommend this. It's well constructed and it is collapsible but your have to unscrew some knobs to do it so no risk of a pup collapsing it on themselves and this one is about 3x2x2 and it's $85. https://a.co/d/0cUYhac1