You are too late to use online TurboTax for a 2021 tax return. The only way to use TurboTax now for 2021 is to purchase the CD/download and use it on a full PC or Mac. You cannot use it on a mobile device of any sort. And the return cannot be e-filed; it can only be filed by mail now. You have to print it, sign it in ink and mail it in.
See this TurboTax support FAQ for completing a 2021 tax return originally started using the TurboTax online editions (FAQ has not been updated for 2021 but it is the same as the prior years) https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-finish-a-prior-year-return-that-i-...
Or you might still be able to use the software on the IRS Free File site.
Use this IRS site for other ways to file for free. There are 8 free software versions available from the IRS Free File site
https://apps.irs.gov/app/freeFile/
