Is TurboTax indicating that it's an excess contribution or just that it's a nondeductible contribution. Either situation would cause it to not be present on Schedule 1 as a deduction.
If it's not an excess contribution, it would be nondeductible if you were covered by a workplace retirement plan (including a self-employed retirement plan) and your modified AGI for the purpose is above the threshold based on your filing status.
Examine the IRA Deduction Worksheet ("IRA Worksheet" in the forms list).
