If you received a federal extension to file, Oregon will allow the same extension. Don't include a copy of your federal extension with your Oregon return. Keep it with your records.
An extension doesn't mean more time to pay.
You must pay all of the tax you expect to owe by May 17, 2021, or you may owe a late-payment penalty. If you can't pay all of the tax you expect to owe, pay what you can. If you don't pay all of the tax due, you'll owe a late-payment penalty as well as interest on any unpaid tax starting after May 17, 2021 until the date of your payment.
If you have a federal extension or need an extension for Oregon only, send your payment by May 17, 2021 using Form OR-40-V . Check the "original return" box on the voucher if you're mailing your payment or paying in person.