For 2021, I think I would enter it on line 6 of the EIC Worksheet as a negative number.  That should correct the amount for EIC.  The other option is to check the box saying it was prison/inmate income.

I'm not sure, but the taxpayer may still get an IRS notice about it. 

For 2022, the W-2 worksheet has a new line "K" that I suspect will work and automatically back it out.  But I haven't tinkered with it much yet.