This would require updating the theme code by adding the kiwi snippet. 

First, open the theme code editor, and open the file featured-product.liquid

Next in the liquid file, find where you want the size chart to display, and then insert the following code:

<!-- START KiwiSizing code !-->
<div id="KiwiSizingChart"
  data-collections="{{ product.collections | map: 'id' | join: ','}}"
  data-tags="{{ product.tags | join: ',' | escape}}"
  data-vendor="{{product.vendor | escape}}"
  data-product-images="{{product.images | json| escape}}"
  data-type="{{product.type | escape}}">
<!-- END KiwiSizing code !-->

For more information on the snipet, see this guide: