The IRS recommends omitting the apostrophe, and entering your name with no spaces:
The only characters allowed are alpha, ampersand (&), hyphen (-), less-than sign (<), and space. The left-most position must be an alpha character. The less-than sign replaces the intervening space to identify the primary taxpayer's last name. It cannot be preceded by or followed by a space.
2. All apostrophes (') and any other punctuation characters, except the hyphen (-), must be omitted from names and the alphabetic characters shifted to the left in their place. Example: O'Shea = OSHEA
https://www.irs.gov/pub/irs-pdf/p4164.pdf
