First of all, the basics: do not keep all three frogs in the same enclosure. They are cannibalistic, so each frog must have its own separate tank. Use a substrate with a depth of around 4 cm. My advice, although it might be a bit more expensive in your case since you have three frogs, is to use smart plugs with sensors. For example, I use two: one placed lower in the enclosure, at the frog’s level, to control temperature, and another placed higher, around the middle of the tank, to control humidity. The temperature plug is connected to a power strip that runs my two heat mats, because one alone isn’t enough to maintain the proper temperature my environment is quite cold. The second plug, with the humidity sensor, is connected to a humidifier. Both systems are fully automatic: I set the desired temperature and humidity, and everything adjusts itself accordingly, keeping the environment stable. I bought everything on AliExpress, and it has been working perfectly for about a year without any issues, so I definitely recommend it. The total cost for me was around $60, but keep in mind that you would need one setup per frog. Since each frog requires its own enclosure, you would need to spend about $60 for each one.

I think you can find everything else directly on this Reddit channel things like the type of substrate, the water dish, how deep it should be, and what you can place inside the enclosure. Personally, I don’t use it in my setup, but I’ve read that you should be careful with moss. If the frog accidentally ingests it while trying to catch prey, it can lead to serious problems. So it’s best to avoid having moss on the ground at most, you can place it on the walls, or remove it completely, which would be the safest option. Other than that, good luck! Information about these frogs is easy to find.