Use this CSS class together with the anchor name in ID attribute

<div class="a-anchor" id="example-anchor"></div>
<section class="...">
    ...

The smooth scrolling effect does CSS property. As well as offset before anchor that equals to header height. Offset height is dynamic according 'headroom' state. Setup your header height in Sass variables before importing module to overwrite default values:

$header-height: 130px !default;
$header-height-mobile: 80px !default;

@import "~aitomic-a-anchor/src/a-anchor";