I can't tell if I ever submitted my 2021 taxes

What does it say in your account for the 2021 return?  Does it say "accepted?"   If it says anything other than "accepted"---like "rejected", "printed," or "ready to mail"  -- if you did not put it in an envelope and take it to a mailbox yourself it was never filed.  TurboTax does not mail it for you.   If you forgot to file it, then print it, sign and date it in ink, and mail it in.

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.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

Another approach is to ask the IRS if they have a copy of your prior year return.

You can ask online for a Transcript of your prior year returns. A transcript is a listing of line numbers and dollar amounts. it is not a copy of the 1040 and supporting schedules, but you should be able to use the transcript to get any data value you need.

Try to get the Transcript online, because mailing is slow now.

Please see Get Transcript at the IRS website.