PayPal Integration Error

I'm trying to use the PayPal widget.  I'm getting the following error when I do the submit:

The paypal sandbox account that I am using (email: d-nblum-facilitator@nc.rr.com) gives me the above message.  I wonder if I need to supply the signature or password some place in the jotform paypal widget.  Here's the info from the paypal account:

I don't recognize any field in the paypal widget where I would supply this....yet I would anticipate a password or signature...or something would be required.

Help please.  Maybe there's a different issue?

Here's my form:  https://form.jotform.com/71256969984982

We are sorry for the problem you have experienced. 

I checked your integration setting on your form and your form setup seems to be fine. I've tried to submit your form and I was directed to PayPal site.

The error message looks that there could be an issue on PayPal side. Could you please also check your credentials entered to integration? You may also consider to contact PayPal support to double check if your Merchant account is fine.

If you have more questions, please feel free to contact us.