To add labels to a layer, follow these simple steps:

1. Open the LAYER ADMIN panel. 
   
2. Select the layer to which you'd like to add labels.
   
3. Scroll down to the 'Label' section, and click the toggle bar that's labeled 'Label features in this layer'.
   
   
   
4. In the pop-up box, select the field you would like as your label field.
   
5. Select the color and size of the labels, and choose whether to allow the labels to overlap.
   
6. Click 'save'.