I have five incomplete payments. What happens if I complete them manually? My own submission of the form I created came back as incomplete. It does ho

If you manually complete the payments, they will only appear on the submissions list, but they will not charge the customer automatically, they will need to manually send you the payment for that submission.

I would recommend you to check these guides about incomplete payments on PayPal as you're using this integration on your forms: 

https://www.jotform.com/help/564-how-to-view-incomplete-payments-of-your-payment-forms/

https://www.jotform.com/help/272-Paypal-Incomplete-Payments-FAQ

I hope this helps.