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-product="{{product.id}}"
  data-vendor="{{product.vendor | escape}}"
  data-product-name="{{product.title}}"
  data-product-images="{{product.images | json| escape}}"
  data-type="{{product.type | escape}}">
</div>
<!-- END KiwiSizing code !-->


For more information on the snipet, see this guide: https://help.kiwisizing.com/a/solutions/articles/44001121637