Can I still ask for an extension?

[DoninGA]

A 2023 extension request had to be filed on or before April 15, 2024.

If you do not have taxes owed or have a tax refund there are no penalties for filing after the due date of the 2023 tax return.

[Opus 17]

After April 15, an extension cannot be obtained electronically, and can't be obtained unless you are living overseas.  If you missed the deadline you are just late.  File as soon as you can.  If you think you will owe taxes, you can make an estimated payment at www.irs.gov/payments.  Making a payment as soon as you can will reduce the interest you may eventually be charged.  You will get credit for the payment on your tax return and if you overpay you will get a refund.  If you expect a refund, there is no penalty for filing late.  

If you are overseas, you have an automatic extension until June 15, but you must file your return by mail to claim it.  You also have until June 15 to request an extension to the final deadline of October 15, but this must also be requested by mail.