Hello,
In this demo, the categories are set to display in a carousel by default. However, since the number of categories is limited to 4 in the custom query, the carousel is not functioning.
To fix this, navigate to Pages > Edit Home Page with Elementor > Edit Product Categories widget, and update the data source to either Custom Query or WooCommerce. Then, increase the number of categories. Once more categories are available, the carousel arrows will appear.
Best Regards,