I have purchased and downloaded the Deluxe version, and "its deductible" does not let me add items. It seems to be missing the itemize items and the + tab.

I have used the itsdeductible online version on the Intuit site for many years.  Bring up itsdeductible online, create your account,password, etc. and then you can enter charitable contributions (goods, money, etc). You can look up charities, enter new charities, and maintain multi year records. When you are all done and satisfied everything is right online, logout. You can then launch TT Deluxe on your computer, go to contributions,  and select  to have it download them from the site.  You will provide your itsdeductible user name and password when TT asks for them.  Bingo, there are all in your return. The online version lets you enter them at any time during the year.