title: How to add layers on mapbox?
body: <p>I just checked the documentation to add the layer on mapbox. But it is not working for me.</p>
  
  <p><a href="https://www.mapbox.com/help/adding-custom-layers/" rel="nofollow">https://www.mapbox.com/help/adding-custom-layers/</a> </p>
  
  <p>Please have a look. 
  When I am trying to add a layer it pops up a blank window and there is no provision to add a layer. 
  What is the mistake? </p>