On the bag's scan page and the order page those buttons only render when Business: Labels > Bags status : Show mark delivered/returned button is Yes and you are logged in as an admin. Mark Bag Returned only appears once a bag has been marked Delivered. On the bag's own scan page (opened from its QR code), the Returned button is additionally hidden outright when the bag type is Not Returnable — but on the order page and on the Bags reports it can still appear for a Not Returnable bag; clicking it there is simply rejected without changing the status or crediting a fee. On the Bags reports the buttons always show to users with the report permission (there's no separate config check there), and any status change is only applied if it follows the En Route → Delivered → Returned order.