You still can but it will be a bit complicated. Assuming that you filed your 2017 federal return with TurboTax, you can purchase the prior year software and download your .taxfile from your Tax Timeline. You will have to go through the motions in the federal section as if you are filing it again (but the information should be filled out already) and then Add the State return and finish the state. You will have to print and mail the state return.
You can follow the general instructions in this article