If you received a federal extension to file, Oregon will allow the same extension. Be sure to check the "Extension filed" box on your Oregon return. 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 April 15, 2019, 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 interest on any unpaid tax starting after April 15, 2019 until the date of your payment plus penalty.
If you have a federal extension or need an extension for Oregon only, send your payment by April 15, 2019 using Form OR-40-V. Check the "Extension payment" box on the voucher if you're mailing your payment or paying in person.