There's lots of options, at least in the US:

• https://www.amazon.com/Doskocil-Petmate-Litter-Mouse-Jumbo/dp/B00JOZ48KK/
• https://www.amazon.com/Van-Ness-Litter-Assorted-Colors/dp/B0027JF0NO
• https://www.amazon.com/Petmate-Giant-Litter-High-Capacity-Color/dp/B0135X6ZBG/
• https://www.amazon.com/Van-Ness-Control-Extra-Enclosed/dp/B0002ASCGM/
• https://kittygohere.com/product/jumbo-gray-litter-pan/
• https://agrifeedpetsupply.com/products/nvr-miss-litterbox
• https://www.amazon.com/iPrimio-Enclosed-Sides-Stainless-Litter/dp/B07WSF1D8B

And you can also DIY your own with under the bed storage bins:

• https://www.walmart.com/ip/Sterilite-41-Quart-39-L-Storage-Box-Walmart-White/10401039
• https://www.ikea.com/us/en/p/sockerbit-storage-box-with-lid-white-20411524/