Custom nether structure generates above the bedrock

Hi ! I'm trying to generate a custom structure in the nether, but it currently generates above the upper bedrock layer. How can I control the height at which it spawns while letting it generate anywhere between the sea level and the upmost bedrock layer ? Here's my current structure.json: json { "type": "minecraft:jigsaw", "biomes": "#letsdoaddon-structures:has_structure/crimson_vinery", "spawn_overrides": {}, "start_pool": "letsdoaddon-structures:crimson_vinery", "size": 3, "project_start_to_heightmap": "WORLD_SURFACE_WG", "step": "surface_structures", "terrain_adaptation": "beard_thin", "start_height": { "absolute": 0 }, "max_distance_from_center": 80, "use_expansion_hack": false } Thanks !