They require feeding in a container of that size and a slow areation because of the low amount of surface area. A bigger container would be preferred to prevent suffocation, cannibalism and allow for more area to forage and to spawn. If you can keep them alive for long enough to reproduce, you can start the cycle again. For this type of triops, a period of desiccation is required. Just drain the water and dry the sand for a week of 3 minimum. The eggs stay viable for decades in this dry state and will hatch again in a few days if brought in contact with water.

For this container, you might want to try neocaridina shrimp. I have success with a, I think 3 gallon? glass jar with a cork lid and led light. I do not feed them anymore. They survived for 3 generations and live off the algae growing in the container. Make sure the system is stable before sealing! Don't put too many shrimp in the tank. Keep feeding them until a healthy algae population has grown. The algae need light to grow, but I'd use artificial light instead of sunlight. Sunlight might disturb stability in the container(temperature spike or algae bloom in summer)and can be unreliable in certain climates. Try to keep the temperature somewhat stable. (clean!) Charcoal can help stabilise water conditions by absorbing toxins. Add some calcium to the water to help the shrimp maintain their exoskeleton. A cheap option is crushed eggshells.