Hello,

This demo is using a custom layout for archive pages. Navigate to layouts >If you are using layout, edit this layout with page builder and add the product categories widget and configure.

If you are not using custom layout, You can use WooCommerce builder of WoodMart allowing you to create custom templates for Product, Product Categories pages and other functional pages that are not editable by default. Here is the documentation:
https://xtemos.com/docs-topic/woodmart-woocommerce-layout-builder/

If you have any questions feel free to contact us.

Best Regards.