To access your current or prior year online tax returns sign onto the TurboTax website with the userID you used to create the account - https://myturbotax.intuit.com/
Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show. Click on 2018
What is the status of the 2018 tax return? If the status is anything other than Accepted then the tax return was not e-filed. If you did not print and mail the federal tax return then the return was never filed.
Click on Download/print return (PDF)
A 2018 tax return can only be printed and mailed, it cannot be e-filed.