How to round pebble action bar edges?


I’m new to pebble app development and relatively new to programming. I’m trying to create a simple action bar over a text layer. My issue regards its shape. The documentation clearly depicts the action bar as rounded while following its instructions leads to a chunky rectangular vertical rectangle. My question is this: is the vertical rectangle default behavior? If so, can it be changed to the rounded style from within the default api? If not, what steps might I need to take to achieve the rounded (and frankly more attractive) rounded look?