Since you put in banking information for a direct debit, I would not send in another payment. As long as you filed on or before the due date, you are considered as paying on time even if the money has not been deducted from your account yet. Your e-file transmission sheet proves you filed on time & entered your payment information. In the meantime, keep an eye on your bank account — if you still don't see the debit 7–10 days after your return has been accepted, you can contact your state tax agency, about your payment.
https://revenue.delaware.gov/services/PIT_Cont
