TurboTax Online is not available for 2017. You'll need to purchase and download the software for tax year 2017.
Please see this link for instructions on filing a prior year return.
You are using the wrong software if everything you are seeing is for tax year 2018. If you started a return in online 2018 software, it is now too late to e-file that return anyhow--luckily for you. Scrap it, and you have to start over in the correct 2017 software.
To file a return for a prior tax year
If you need to prepare a return for 2016, 2017, or 2018 you can purchase and download desktop software to do it, then print, sign, and mail the return(s) Make sure you purchase 2017.
Remember to prepare your state return as well—if you live in a state that has a state income tax.
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
Note: The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac. It cannot be used on a mobile device.