minecraft-bedrock-json-schemas/source/behavior/blocks/format/events/set_block.json

{
  "$id": "blockception.minecraft.behavior.block.events.set_block",
  "type": "object",
  "description": "Sets this block to another block type.",
  "title": "Set Block",
  "additionalProperties": false,
  "properties": {
    "block_type": {
      "$ref": "../../../../general/block/reference.json",
      "default": "",
      "description": "The type of block to set.",
      "title": "Block Type"
    }
  }
}