On the PA tax return where do you enter the application of your 2019 overpayment to your 2020 tax balance?

The overpayment from your 2019 state tax return that you applied to 2020 will serve as a credit against your 2020 state tax liability and has to be entered in TurboTax.

You enter the amount in the Federal section and TurboTax will transfer it to your state return.

You can enter the amount applied to your 2020 state tax by following these steps:

1. In TurboTax, open your tax return
2. Click on Federal in the left-hand column, then Deductions & Credits on top of the screen
3. Scroll down to All tax breaks, locate the section named Estimates and Other Taxes Paid and click Show more
4. Click on Start next to Income taxes Paid
5. On the next page, click Start next to 2019 refund applied to 2020 state taxes.

Thank you. I did eventually find it after I posted the question.