Hi and welcome to Just Answer!
Assuming - you are Single - with income $72,000 is spousal support, and $40,000 in the Wisconsin Powerball winnings - total $112,000.
Assuming standard deduction, no dependents, no other deductions or credits - your estimated tax liability is $22,300.
Considering that $9996 in federal taxes were withheld - your additional tax liability would be ~$12,300.
What you might do to reduce your tax liability?
Itemize your deductions and deduct additional gabbling losses if you have any.
Otherwise - I am not clear how the IRS determine your additional tax liability.
Please provide exact text of the IRS note.