I already submitted my efile. But I don't remember seeing where to enter real property tax payment. How to I submit that now?

[DawnC]

If your return gets rejected, you can add the property tax and resubmit your return.   Where do I enter property tax deductions?

However, if your return is accepted, you will need to wait until the return is fully processed and then file an amendment to add the deduction.   

Property tax deductions are itemized deductions.   Unless you itemize deductions, the amount you enter will have no effect on your tax refund or tax-due amount.   So, if you take the Standard Deduction, you don't need to enter it at all  - - unless it is enough to make itemizing a better option.    You can look at line 12 of your tax return (Form 1040) to see if you are taking the standard deduction or itemizing.  

What are itemized deductions?