Obvious MIstake

I have used Turbotax for years, mostly because I have investments and don't know how to do that portion of the tax return myself.  Other than the investments, I understand the 1040 and how it works.  I am now preparing my 2021 taxes and there is an obvious error in the calculations.   Turbotax shows that my taxable income is just over $3,000.  But on the next line, "Tax Due", it shows $0.   This cannot be right.  How do I fix this?