Log in, open your return and go through the FILE tab, through the 3 steps all the way to the very end and hit the big orange Transmit Returns Now button.
How to Efile
https://ttlc.intuit.com/community/e-file/help/how-do-i-e-file-my-personal-individual-tax-return/00/2...
Or does your account say Ready to Mail?
How to change from Mail to Efile
https://ttlc.intuit.com/community/e-file/help/how-do-i-change-from-mail-to-e-file-in-turbotax-online...
