You never pay tax on contributions so that part is confusing. When you make a Traditional IRA contribution you can take a deduction for it or make it non-deductible. When you enter the contribution it should ask if you want the deduction.
You can't use pretax dollars to make a contribution. You can rollover pretax money like from a 401K plan. That is not a contribution but a Rollover.
Or are you asking about when you take a distribution?
You can type ira contributions in the search bar at the top and it will give you a JUMP TO link to go right to it.
OR Enter IRA contributions under
Federal On left
Deductions and Credits
Then scroll down to Retirement and Investments
Traditional and ROTH IRA Contributions - Click the Start or Update button
