Shipping multiple SKUs in one box

First time seller here. So I’m shipping my first box of product to Amazon. On the “Send to Amazon” page, they said I can ship all 6 of my SKUs in one box, packed as individual units.

My question is, do I need to differentiate the products somehow, so Amazon knows which units are tied to their particular SKUs? Or can I just pack all of my individual units randomly? There is no branding or packaging that differentiates the products.