How To Add A Custom Liquid

Go to Online Store > Themes

Click Customize on your active theme

Navigate to the page you want to edit (e.g., home page, product page)

Click Add Section

Choose Custom Liquid

Paste your Liquid code in the editor (e.g.):

<h2>{{ product.title }}</h2>
<p>{{ product.description }}</p>
{% if product.metafields.custom.my_field %}
  <p>Extra Info: {{ product.metafields.custom.my_field }}</p>
{% endif %}

Click Save