Square Payment Form Error

A customer emailed me and said they are receiving this error (see attachment) when trying to make a payment. The form has been working fine for months and I've made no changes to it...so not sure what's up.

The form is located here: https://form.jotform.com/73045251284957

From what I can see at your Square Integration, it seems that everything is set up correctly.

But, to be sure, I kindly ask you to fill your form in a Test mode:

Let us know how it goes, in order to investigate further.