How can I file 2017 and 2018 both on here

[CarolynM]

Unfortunately, you can't.

The on-line programs only support the filing of 2018 tax returns.

You will need to use a  CD/Download product to complete your 2017 tax return. You will need to print and mail because the IRS does not accept prior year returns for e-file. 

Follow this link for product information: Past Years Products

When you e-file your 2018 tax return, you will report your prior AGI as $0 because the IRS is receiving your prior return after October, 2018.