My issue is that in the example, they first add layers to a blank map. I have the layers already on my map from adding to my style in Studio. So, I can take out the map.addSource and map.addLayers parts of the code because I don't need to add layers. But then when creating the toggle button, it doesn't point to the layers from my Studio style. What do I need to add to reference the two layers already in my style?