minecraft-assets/data/minecraft/worldgen/structure_set/buried_treasures.json

{
  "placement": {
    "type": "minecraft:random_spread",
    "frequency": 0.01,
    "frequency_reduction_method": "legacy_type_2",
    "locate_offset": [
      9,
      0,
      9
    ],
    "salt": 0,
    "separation": 0,
    "spacing": 1
  },
  "structures": [
    {
      "structure": "minecraft:buried_treasure",
      "weight": 1
    }
  ]
}