Amazon pay button stops working when I add: data-ap-seller-order-id=”Some-ID”

I generated a pay button via Amazon Pay (Sandbox View) which works fine. I need to add data-ap-seller-order-id="Some-ID" to the code (because when you generate a button data-ap-seller-order-id="" is not among the options), however, when I do add it manually to the code the button stops working. Their parameter values page specifies that option:

https://pay.amazon.com/us/developer/documentation/express/201737770

This is the error I get when I add…

Amazon pay button stops working when I add: data-ap-seller-order-id="Some-ID"