How to make the structure spawn underground?

{ "biomes": "minecraft:cherry_grove", "adapt_noise": false, "liquid_settings": "ignore_waterlogging", "spawn_overrides": {}, "type": "minecraft:jigsaw", "start_pool": "morevillages:village_underground/entrance", "size": 7, "step": "surface_structures", "start_height": { "absolute": 0 }, "project_start_to_heightmap": "WORLD_SURFACE_WG", "max_distance_from_center": 116, "terrain_adaptation": "beard_thin", "use_expansion_hack": false }