No --- e-filing has been permanently closed for 2018 returns since October of 2019. Does the IRS say you did not file the return---or that you did not pay your tax due? Your only proof that you paid would be your own bank/credit records. It is unlikely that the IRS would send you a letter just to say you did not file---they must want money you owe.
It is possible that your return was rejected and you did not notice. When you e-file you get back two emails. The first one only says that your return was submitted. But the next one tells you if the return was accepted or rejected. Look in your account for 2018---does it say the return was accepted?
If the IRS needs your 2018 return then print it, sign it , and mail it.
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.**
