After you file

Per the IRS form 1040 instructions page 76

https://www.irs.gov/pub/irs-pdf/i1040gi.pdf

If your return is signed by
a representative for you, you must have
a power of attorney attached that specifically
authorizes the representative to
sign your return. To do this, you can use
Form 2848.


TurboTax does not support the 2848 form but it can be downloaded from the IRS site.

Form:  https://www.irs.gov/pub/irs-pdf/f2848.pdf
Instructions: https://www.irs.gov/pub/irs-pdf/i2848.pdf


You would have to physically sign a paper return and mail with the attached POA.
**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.**