Those are normally reported on your W-2 in box 12 with code W.
But, if they are not reported there, go to the Deductions and Credits > Medical > 1099-SA, HSA, MSA section of your return to indicate that you have a Health Savings Account (HSA). Then go through the questions in that section until you see a page titled Did your employer tell you about any other contributions? Answer 'yes' on that page and you will see an entry for contributions not reported on your W-2.