Yes. However, you must still also use the IRS special power of attorney form which is 2848. If you can’t have the taxpayer fill out part one of form 2848, you will still need to fill out part two which is the representative’s statement.
If you are able to e-file because you know the person‘s information, then after successfully e-filing the return, you must mail the signed form to 848 along with a copy of your power of attorney to the IRS using another form called 8453 as a cover page. If you can’t e-file, you will mail the original return to the IRS where you will sign your name in the signature with the notation power of attorney. Attach a copy of your power of attorney and form 2848 to the return when you mail it.
https://www.irs.gov/pub/irs-pdf/f2848.pdf
https://www.irs.gov/pub/irs-pdf/f8453.pdf
