AMP form submission error for WP Paypal

The paypal button on this page works fine for a desktop computer and the payment is handled properly but when we try to purchase from a mobile device we get a message “Submission Failed” and when I select more info, I get sent to an information page about AMP forms. There seems to be an issue how the form is being handled by mobile devices, are you able to let me know why this is happening please and what the fix is?

The short code I am using is, [wp_paypal button=”buynow” name=”Module Set” amount=”20.00″ return=”https://aramaicnt.net/download/modules-download/”%5D

The page I need help with: [log in to see the link]