HHGames/data/herohost/dimension/world.json

{
    "type": "herohost:world_type",
    "generator": {
        "type": "minecraft:flat",
        "settings": {
            "biome": "herohost:biome",
            "layers": [{
                "block": "minecraft:air",
                "height": 1
            }],
            "structure_overrides": []
        }
    }
}