How did you file 2017? Did you do it by hand and mail it in? Or buy the 2017 Desktop program? I ask because you can't use the Online version and you can't efile it. Online is only good for 2019 now but some people used it to do a prior year.
The IRS uses 2018 or 2019 to send the Stimulus Check. If you didn't file those years you can sign up on the non-Filer page.
Look up your status here or fill out a non-filers form
https://www.irs.gov/coronavirus/economic-impact-payments