jQuery Simple Example

HTML

<script src="//www.addressfinder.co.nz/assets/v2/widget.js"></script>
<body>
  <section>Твой section</section>
</body>

CSS

body {
  min-height: 1200px;
}

section {
  background-color: yellow;
}

JavaScript

let section = $('section');
$(window).scroll(magic);
function magic() {
  window.pageYOffset > 500 
    ? section.height(500) 
    : section.height(200)
};