To enter alimony paid -
Click on Federal Taxes (Personal using Home and Business)
Click on Deductions and Credits
Click on I'll choose what I work on (if shown)
Scroll down to Other Deductions and Credits
On Alimony Paid, click the start or update button
Or enter alimony paid in the Search box located in the upper right of the program screen. Click on Jump to alimony paid
When you say it is not letting you deduct it, does that mean you entered the alimony but it did not decrease your taxable income?
If so, double check that you did NOT check the box under where you enter the alimony as this will make it not deductible. If it is not showing as deductible go back and edit your entries and double check that the box is NOT checked.
If you are trying to enter your alimony, this is under Other Deductions and Credits. You can click the search bar and enter Alimony then Jump to Alimony to enter your alimony payments.