Great advice, but a quick note that this species rarely if ever produces visible urates. Manouria Emys are common here, and I'm in various Facebook and WhatsApp groups for species with hundreds of owners. Only once did someone post something which looked like urates and I think we determined it was probably something else.You should be doing his soaks in a container he cannot climb out of, but it is good for him to try. The physical movement (like a human treadmill) usually helps them poop & pee, as well as giving the ones sleeping all day some exercise which they need to digest their foods. Soaks for the young should be 20-30 minutes in luke warm water daily, keeping the water warm throughout the soak.
The added benefit for having them poop & pee in their soaks is less cleanup for you in their enclosure. It gives you a chance to see if they're drinking water in their soaks or have visible urates in their pee. Urates can be a symptom of under-hydration.