Well-you cannot e-file a 2018 return. You have to print, sign and mail the 2018 state return. E-filing for 2018 has been closed since mid-October of 2019.
In order to prepare a 2018 state return you will need the desktop software that you download/install to a full PC or Mac. Or you could just get the state forms and prepare them by hand on paper if you prefer.
https://ttlc.intuit.com/questions/1900990-how-do-i-file-a-prior-year-tax-return
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
