Error: An Amazon payment method was not chosen

Hi,

Does anyone know what the problem is with this?

I have set up the Woocommerce ‘Amazon Payments’ plugin on my website, and when testing with sandbox enabled and using an amazon generated test user, i get ‘Error: An Amazon payment method was not chosen.’

i have tried choosing all the payment options amazon generated, but to no avail

Any help would be very helpful

Thanks