We paid 2020 estimated tax with four vouchers for four quarters ( form 1040-ES) throughout 2020 . How is it reflected in this current filing? How can we claim this?

On the Deductions & Credits page....if you scroll down the menu on that page , there is a specific entry section & line for Estimated tax payments.   Make sure you enter the exact dates you paid ... don't use the default due-by dates.

If enter your estimated tax payments in TurboTax, you can follow these steps: 

1. Open your tax return.
2. Search for estimated tax payments with the magnifying glass tool on the top of the page. 
3. Click on the Jump to estimated tax payments link at the top of the search results.
4. Click on Start next to Federal estimated taxes for 2020.
5. Select yes for the question Did you pay federal estimated taxes for 2020?
6. Follow the on-screen instructions.