This is the "Add to Cart" button on the product detail page of the Shopify theme "Dawn", but it would be nice to display the cart icon used in the header. Here is an example of how to do that.
Example of settings to display a cart (bag) icon on the "Add to Cart" button on the product detail page of the theme "Dawn"

[How to set it up] Add code to "buy-button.liquid" and "section-main-product.css"

