It might think you filed by mailing it.
If you haven't mailed it yet you can try to switch to efile.
Click on Add a State to let you back into your retun.
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/00/26985