If you have not mailed or efiled your return then you DO NOT amend it. You can just change it and file it. Click on Add A State to let you back into your return.
Then you can try to switch to efile.
https://ttlc.intuit.com/community/e-file/help/how-do-i-change-from-mail-to-e-file-in-turbotax-online...
