Forge 1.20.1 Custom entities not spawning

[DinoPawz]

I cannot get my custom entities to spawn naturally in the world. They spawn successfully from a spawn egg. I have tried a video and did what they said, but still doesn't work.

 

I put this in the entity's class:

 public static boolean canSpawn(EntityType<CarnAchillobator> entityType, ServerLevelAccessor levelAccessor, MobSpawnType mobSpawnType, BlockPos pos, RandomSource randomSource) {
        return Monster.checkMonsterSpawnRules(entityType, levelAccessor, mobSpawnType, pos, randomSource);
    }

 

I this in the main class:

 @SubscribeEvent
        public static void registerSpawnPlacementsEvent(@NotNull SpawnPlacementRegisterEvent event) {
           
            event.register(ModEntities.ACHILLOBATOR.get(), SpawnPlacements.Type.ON_GROUND, Heightmap.Types.WORLD_SURFACE, CarnAchillobator::canSpawn, SpawnPlacementRegisterEvent.Operation.AND);
       

In the modid/biome_modifier directory, spawn_achillobator.json file:

{
  "type": "forge:add_spawns",
  "biomes": [
    "minecraft:jungle",
    "minecraft:sparse_jungle",
    "minecraft:windswept_forest",
    "minecraft:dark_forest",
    "minecraft:old_growth_birch_forest"
  ],
  "spawners": {
    "type": "wilddinos:achillobator",
    "weight": 100,
    "minCount": 1,
    "maxCount": 1
  }
}