<div style="background-image: url({{=URL('static', 'images/byo.jpg', scheme=True)}})"></div>
<div style="background-image: url({{=URL('static', 'images/byo.jpg', scheme=True, width="200", height="150", )}})"></div>
<div style="background-image: url({{=URL('static', 'images/byo.jpg', scheme=True, _width="200", _height="150")}})"></div>