No, estimated tax payments are not what is withheld from your salary. Estimated tax payments are additional payments that you send directly to the IRS yourself, usually quarterly. You would typically do that if you have significant income from which no tax is withheld, such as business or self-employment income, or capital gains. If you did not make any estimated tax payments, don't enter anything.
The money that is withheld from your salary is called withholding, not estimated tax. TurboTax will get the correct amount of tax withheld from box 2 of your W-2.
