minecraft-assets/data/minecraft/worldgen/template_pool/ancient_city/sculk.json

{
  "elements": [
    {
      "element": {
        "element_type": "minecraft:feature_pool_element",
        "feature": "minecraft:sculk_patch_ancient_city",
        "projection": "rigid"
      },
      "weight": 6
    },
    {
      "element": {
        "element_type": "minecraft:empty_pool_element"
      },
      "weight": 1
    }
  ],
  "fallback": "minecraft:empty"
}