Instead of adding a discount during the abandoned cart automation I would like to automatically add an additional item to a customers cart. How do I put that into the automation. This way I know to a
I think you should be able to do that with permalinks:
https://help.shopify.com/en/manual/products/details/cart-permalink
You might want to create a permalink that has all of the existing items in the cart in it and then add that other bonus item.
Cool idea btw - discounts on abandoned cart emails are probably overdone.