This is a code example that automatically generates a breadcrumb list from Shopify's main menu. It is not suitable for full-scale SEO measures because it is only generated for pages set in the menu, but it is easy to use because it automatically reads and generates the hierarchical structure.
How to automatically generate breadcrumbs from store menus with the Dawn theme

Setup Step 1: Insert the code into "header.liquid"

Setup Step 2: Create a main menu with a remodeling structure

