You cannot e-file a 2019 return. E-filing for 2019 has been closed permanently since October 15, 2020. The only way to file a 2019 tax return is to print it, sign it and date it in ink and mail it in an envelope.
If you are getting a refund there is no penalty for filing after the deadline. If you owe tax for your 2019 return your interest and penalties have been adding up since last October, so mail it in asap and pay your tax due. You can pay directly on the IRS site.
https://www.irs.gov/payments/direct-pay
https://ttlc.intuit.com/community/tax-payments/help/how-can-i-pay-my-federal-taxes/00/26212
https://ttlc.intuit.com/community/tax-payments/help/how-do-i-pay-my-irs-tax-due-with-a-check-or-mone...
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.
Federal and state returns must be in separate envelopes and they are mailed to different addresses. Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.
**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.**
