The layers panel shows a list of all map layers that are available. It allows you to toggle layer visibility and change layer specific settings.
On small screens, it may be helpful to hide the layers panel when you’re not using it. You can close it by clicking the X in the upper right corner. You can reopen it by clicking the Layers tab again.
There are a couple reasons you may not being seeing a layer that you’ve enabled.
Zoom Level: You might not be zoomed in far enough to see the layer. To improve map performance, many layers are only visible at closer zoom levels. Try zooming in to see if the layer becomes visible.
No Features in View: The layer might not have any features within the current map area you're viewing. Try panning to a different area to see if the layer appears.