Can someone please help me. I don't know what turbo tax product I should use. I don't have a job at the moment and my ex only pays me alimony sometimes.

If alimony is your only income it is unclear whether you even need to file a tax return.    When was the divorce finalized?   Before or after the end of 2018?   If the divorce was final before the end of 2018 the alimony is taxable income.

Who has to file?

http://www.irs.gov/uac/Do-I-Need-to-File-a-Tax-Return%3F

It depends on the date of your divorce agreement.  If your divorce agreement is on or after January 1, 2019, it is not reportable on your tax return.  So if you have no job, and no other income, you would not need to file a tax return.

If the divorce agreement date is prior to January 1, 2019, then you could report it using TurboTax Deluxe, if you have income greater than your standard deduction.