I tested PayPal form but it is still in the "Incomplete payments".

I don't know how to set up the "payment gateway" with PayPal. I have done a test donation, but it is still in the "incomplete payments" location on JotForm. I also received a notice from PayPal that I needed to do a confirmation email; I have written to them also because following their directions didn't work. Help!

Hello,

I did check your account and found that you have added PayPal payment tool and integrated it with your PayPal account correctly. 

I also received a notice from PayPal that I needed to do a confirmation email

I am not sure if I have understood your issue correctly. Do you have a new PayPal account? t could be limited and you need to verify your email address and other task to lift the limits. Can you please share a screenshot of the email you have received and we will take a look.

When you say that you have submitted your form but it is still in incomplete payments, do you mean to say that you successfully completed the payment? Please note that when form is submitted, users are redirected to Paypal checkout page to process the payment. If the payment is not settled, that submission is marked as incomplete payments. 

If you have received payment successfully in PayPal account but it is still marked as incomplete submissions then IPN of PayPal account must be disabled. I would suggest you to please ensure that IPN of your PayPal account is enabled. The following guide should help you:  https://www.jotform.com/help/276-How-to-Enable-IPN-on-your-Paypal-Account

Thank you!