How can I push additional product data into Google Analytics 4?

How do I push addt’l product data (item category, brand, etc.) into Google Analytics 4? I’ve gone ahead and placed the global site tag into the theme.liquid file and added custom code to the Checkout page. The custom code on the checkout page uses parameters such as line_item.product_id and line_item.title from the liquid file to push basic information into GA4. See attached. But, I’m having trouble figuring out what elements from the liquid file to use to push product category (collection) and brand (vendor) the same way. Any help is appreciated!