There are no second extensions. If you are getting a refund there is no penalty for missing the deadline. If you owe tax due, pay as soon as you are able to. E-filing closes at midnight tonight in your own time zone. After that e-filing deadline you will need to file by mail.
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.