I need proof of timely filing for the 2021 tax year. Where can I acquire this documentation?

[DoninGA]

If you e-filed the tax return using TurboTax you would have received two emails.  The first email was when the tax return was transmitted and will have a date/time included.  The second email would be when the IRS or State either Accepted or Rejected the e-filed tax return.

There is also an Electronic Postmark Report included in the PDF download with will also have the dates and times for the federal return that was e-filed.

If the tax return was printed and mailed, TurboTax has no way to know when the user mailed the return.