The TurboTax online editions for tax year 2018 have shut down for the year after the deadline to file a tax return with extension on October 15, 2019. The TurboTax online editions for tax year 2019 should be available sometime in December 2019.
See this TurboTax support FAQ for completing a 2018 tax return originally started with the online editions - https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-finish-a-prior-year-return-that-i-...
