PayPal will not accept American Express

Any submissions to PayPal using Amex fail. We've called PayPal without any explanation or solution.

May you please share us the form where you're experiencing this issue? 

As far as I know, the payment should go through without any problem as long as the entered credit card info is correct. 

We will wait for your response. 

OK, I found the form based on your screenshot, it seems like you're using the PayPal Express integration, please check that the API information you have entered is correct. 

You may also check if your account allows digital goods selling or you may also try turning off such option: 

I have cloned your form and I can see it redirects to the payment page and allows to pay. 

You may also check the web console in order to see if there are errors, this guide will help you getting the console report: https://www.jotform.com/help/453-How-to-get-a-console-report-from-most-common-browsers 

Please provide us a screenshot of the console following this guide (please do not attach the image on an email response to this thread or it will not reach the forum): https://www.jotform.com/help/438-How-to-Post-Screenshots-to-Our-Support-Forum 

We will wait for your response.