For Line 17, Income Tax that is withheld, on Turobox, where are all these added from? When I add up all of my W2 Box 2, it does not add up to what is showing on Line 17.

Line 17 of which form exactly ?

Is this for a prior year?  For 2020 the withholding on W2 box 2 goes to 1040 line 25a.  

For 2019 line 17 is for withholding from W2 and any 1099 form box 4.  Did you get any 1099R?  Like for a IRA distribution?  Or Social Security SSA-1099?