@fanfare In order to use direct debit on your amended return, you would have had to use direct debit on your original return. The poster did not say they used direct debit on their original return.
If you selected direct-debit when you originally filed, there's no need to send an additional payment by check; your direct debit applies even if you amended your return. Amended returns should not be mailed until after your original return has been processed by the IRS.
