After you file

What they probably want is IRS form 8879 which is a "e-file Signature authorization" form that authorizes a paid tax preparer ( electronic return originator (ERO)) to e-file a tax return on your behalf.  It contains some information from your tax return, the efile pin (electronic signature) and your written signature.
<a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-pdf/f8879.pdf">https://www.irs.gov/pub/irs-pdf/f8879.pdf</a>

TurboTax is *self-prepared* so the 8879 form does not exist since you cannot "authorize" yourself to e-file your own tax return.  Only a paid tax preparer would give you that form that e-files the return for you.   

Some banks are years behind the times and still don't have a clue that many people e-file their own tax returns using tax software so they will not have the "required" 8879 form since it does not exist.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**