It will be great if we can have an option "available for curbside pickup" on individual product pages as well as having the option in the cart.
Hello! You can enable "Curtside pickup" directly from Shopify following these instructions: help.shopify.com/en/manual/shipping/setting-up-and-managing-your-shipping/local-methods/local-pickup#set-up-local-pickup.
Once enabled, you need to show the "Local pickup" block on your product page in order for the content to appear. I have attached a screenshot for reference.