I generated a payment button through Amazon Pay (Sandbox View) that works well. I need to add data-ap-seller-order-id = "Some-ID" to the code (because when a button is generated data-ap-seller-order-id = "" it's not among the options), however, when I manually add it to the code, the button stops working. Your parameter values page specifies that option:
This is the error I get when I add …
The Amazon payment button stops working when I add: data-ap-seller-order-id = "Some-ID"