All you really need is something to hold the litter, though there are more expensive versions that offer a self-cleaning function or grass on top (with waste collecting in a lower pan).  The box should be big enough for your dog to turn around in. The sides should be low enough that your dog can enter by himself, but high enough to stop your dog from peeing out of the box if he lifts his leg. If you buy a box with a hood, consider cutting the top off to make the box easier for your dog to use and for you to clean. Dog litter works best because it has larger pellets that are more absorbent. Dog litter ranges from simple clay to those with activated charcoal to control odor. For your own odor control, simply sprinkle baking soda on the bottom of the box each time before you fill it. You need to remove your dog’s waste every time he eliminates in the box, if possible. Having a scoop and trashcan nearby will make this much easier. You want the box near the places your dog spends most of his time, but also out of the way enough that you’re not watching him.  Don’t place the box near your dog’s food and water, as dogs will not eliminate where they eat. Be aware that dogs have a tendency to dig in their box, especially at first. Place it so that any litter thrown out during digging will not cause too much of a mess. Your cat needs to feel ownership of his box, or he will start peeing outside the box to mark his territory. And if you have two dogs, it’s best to get each of them their own box to avoid similar issues with territoriality.

TL;DR in Vietnamese:
Mua khay nhựa lớn để làm hộp vệ sinh. Cho cát vào hộp. Mua xẻng xúc và thùng rác. Đặt hộp ở nơi thuận tiện, nhưng riêng tư. Đảm bảo mỗi chú chó và mèo đều chó hộp vệ sinh riêng.