In order for you to find out the amount of estimated tax payments you actually made, you may need to check your banking records or contact the taxing authority to see if they can tell you the exact amounts and the dates on which they were paid.
If you created estimated payment vouchers on your 2019 return for tax year 2020 and know you paid them exactly in those amounts and on those dates, you could use that information.
You should have records available of any actual payments made.
However if there is an error, then IRS will adjust the estimated tax payments amount and you may owe underpayment penalties or late payment penalties and interest.
