The item ID for Treasure Chest in Stardew Valley is:
The above cheat code applies to all platforms including PC/Mac (Steam), XBOX One, PS4 and the Nintendo Switch.
Spawning items in Stardew Valley is not done via commands, but rather through a cheat in which you must set your character's name, or the name of an animal, to the item code of the item you wish to spawn surrounded by [ and ].
To spawn this item using an animal's name, visit Marnie's Ranch, speak to Marnie and purchase an animal (we recommend a chicken as it is cheapest). Name the animal  and press OK. You will then receive the treasure chest item.
You can only set your character's name once, at the start of the game (when you create your world), for this reason we recommend you use the animal name method. If you do wish to use this method, first set your character's name to  when creating your save. Whenever you speak to a villager that says your name in dialogue (for example Gus at the Stardrop Saloon) you will be given the treasure chest item.
If you need more help with spawning treasure chest, we have a detailed guide on our blog - click here to visit that page.
The Treasure Chest is one of the rarest items in the game and can only be obtained by playing the Fishing Minigame. At random times when fishing, a treasure chest will appear on your interface with a progression bar. To fill the progression bar, you must keep the green bar behind the treasure chest icon. When progression reaches 100%, you will be given a treasure chest.
Wow, it's loaded with treasure! This is sure to fetch a good price.