To correct a charity's address:
1. Click Federal on the left-hand side menu.
2. Click Deductions & Credits across the top.
3. Scroll down to Charitable Donations and click Show more.
4. Click Start or Revisit by Donations to Charity in 2018.
Click Edit by the one you'd like to change. Make your changes, then Continue to the menu.
That does not work in 2020 Turbo Tax. I had to delete the contribution and go out of "Charitable deductions". Then go back in and add the charity. My issue was a typo with the wrong state so the Zip Code did not match. TT does not let you add an address but deleting gets rid of the erroneous address so I could at least go ahead and E-File. TT did not require an address but in my addition I put the state in the name. The person helping me did not know why the "edit" function didn't work more effectively. The address doesn't impact the amount of anything on the return so it is annoying the TT doesn't let you E-File before trying to change it. And if it isn't deleted and then re-added without an address (or just deleted and give up the deduction!) TT will not allow an E-File.
I don't see a mechanism for changing addresses in Its Deductible either. So will try to change it by deleting and re-adding the charity when I do 2021.