You have until midnight October 17in your own time zone to e-file an original 2021 tax return. Then e-filing for original returns closes. If you have not e-filed the original return by the deadline you will be unable to e-file, so then your return will have to be filed by mail instead.
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.