Changing Vanilla Loot Table is not working

Hello I have a problem I wanted to add some mod items to the Vanilla Chest Loot Tables, but if I spam some or find there are no mod items inside! When I spawne my loot table, all items are inside. Is something wrong with the code? The Path of the Json ist element:chests/simple_dungeon

LootTable Event

  @SubscribeEvent
      public static void onLootLoad(LootTableLoadEvent event) {
          
          if (event.getName().equals(LootTables.CHESTS_JUNGLE_TEMPLE)) {

                event.getTable().addPool(LootPool.builder().addEntry(TableLootEntry.builder(new ResourceLocation("element","simple_dungeon"))).build());
              
            }
          
      }