How can I clear a HSA credit that I did not enter. I HAVE ALREADY PAID TT AND CANNOT USE 'CLEAR AND START OVER'

I am not sure what you mean by HSA credit (there is no such thing), but it seems that you do not have an HSA and want to delete all HSA-related content from your return.

It is possible to accidentally indicate to TurboTax that you had an HSA when perhaps you didn't. If you did not have an HSA, please do the following to remove all traces of HSA information from your return.

NOTE: if you see a question "What type of High Deductible Health Plan did you have any December 1, 2018?" (yes, 2018), be sure to answer "NONE".

1. make a copy of your W-2(s) (if you don't have the paper copies)

2. delete your W-2(s) (use the garbage can icon next to the W-2(s) on the Income screen

*** Desktop***

3. go to View (at the top), choose Forms, and select the desired form. Note the Delete Form button at the bottom of the screen.

*** Online ***

3. go to Tax Tools (on the left), and navigate to Tools->Delete a form

4. delete form(s) 1099-SA (if one), 8889-T, and 8889-S (if one)

5. go back and re-add your W-2(s), preferably adding them manually

6. continue with your return.