Online is only for 2020 returns. If you actually submitted and filed your 2018 info online you have a big problem. It thinks it was for your 2020 return. Now you have to wait until the IRS Accepts or Rejects it. If it Rejects you can change it around to be for 2020 and resend it. BUT if it is Accepted then you need to wait for the IRS to fully process your return and you get the first refund or pay the tax due. Then you can fill out an Amended Return 1040X. So if you have filed DO NOT change or enter anything else into your return until you find out if you have to amend.
Again DO NOT CHANGE or enter anything into your return if you already filed. You will have to start the Amended return with the original return that was filed. How to amend 2020
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/00/27577
When you efile you get back 2 emails. The first email only confirms the transmission and the second email says if it was Accepted or Rejected.
You can check your efiling status here,
https://turbotax.intuit.com/tax-tools/efile-status-lookup/
Do you still need to file a 2018 return or amend one you did file to add this tax form?
