Hi luv11909,
If you have successfully submitted your return by e-filing (and made a payment by direct debit if you had one), and the IRS has accepted your returns, you do not need to mail in anything. Unless you owe money to the IRS and you've chosen to mail in your payment, you should be all set!
However, if you are mailing in your payment, you need to print out a 1040-V. You can follow these instructions:
https://ttlc.intuit.com/replies/3301385
