This is "do-it-yourself" tax software. TurboTax never mails returns for users. A mailed return must have YOUR own signature on it in ink and must have copies of your W-2's and/or 1099's showing tax withheld attached.
If you are getting a refund or do not owe, there is no penalty for filing after the deadline. And...is there some reason you are not e-filing instead of filing by mail? You can switch to e-file if you want to. Then it will all be done electronically and you will not have to mail anything.
But if you choose to file by mail, you have to print it yourself, sign and date it in ink, and mail it yourself.
To change to e-filing:
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
Federal and state returns must be in separate envelopes and they are mailed to different addresses. Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.