I received a letter from the IRS mentioning that "Final Balance Due Reminder – Notice of Intent..." This is related to my 2021 return (Form 1040NR, non-resident alien).

[Mike9241]

Turbotax does not support NR returns. If you can't handle this on your own you'll need the help of a tax professional familiar with your issue. You can contact your state's CPA society or Bar association for a possible recommendation. do so ASAP because the IRS will levy your bank accounts and put liens on assets. your ability to contest the findings could also be jeopardized.