You can just type W4 in the search box at the top of your return , click on Find. Then Click on Jump To and it will take you to the estimated tax payments section. Say no to changing your W-4 and the next screen will start the estimated taxes section.
Or Go to….
Federal Taxes or Personal (Desktop H&B)
Other Tax Situations
Other Tax Forms
Form W-4 and Estimated Taxes - Click the Start or Update button
And don't forget your state. Go to the end of the state section, probably under Other Tax Situations
You use the 2018 program to complete 2019 estimated forms ...
Do I need to make estimated tax payments to the IRS?
Can TurboTax calculate next year's federal estimated taxes?
Can TurboTax calculate the estimated payments for next year's state taxes?