2018? July 14 of this year 2020 or last year? If you used the Online version this year it is only for 2019 returns not 2018. So if it says Ready to Mail it is a good thing it wasn't efiled. And you can not efile 2018 returns. You have to print and mail prior year returns.
Online is only good for 2019 now. If you tried to use the Online version for 2018 and entered 2018 info into the 2019 Online version you can try to clear and start over
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-clear-and-start-over-in-turbotax-onli...
Or you can leave this account and set up a new account to do 2019. How to start another return in the Online version
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-onli...
Then do you still need to file 2018? To do 2018 you have to buy the Desktop Download program here
https://turbotax.intuit.com/personal-taxes/past-years-products/
