Can u tell me which year do i need to amend to get child tax credit payments?

You not amend anything to get the monthly child tax credit payments.   Those payments are for 2021.  If you are eligible to get the payments you can get the child tax credit on your 2021 tax return.   

Some people are already getting those payments based on the children they were able to claim on their 2020 tax returns.   But amending a return now will not get you those payments.   If you have a child who was born in 2021 the IRS portal will allow you to enter information for your child sometime this year--but the portal is not operational yet for that.

TurboTax has no involvement in the monthly child tax credit payments.  The IRS is sending out those payments by direct deposit or by mailed checks or cards.

https://www.irs.gov/credits-deductions/2021-child-tax-credit-and-advance-child-tax-credit-payments-topic-a-general-information

You can click the links on the right hand side of the page that is linked for you above for further information.

If you are referring to the Advance Child Tax Credit being issued by the IRS for eligible dependents that were on a 2020 tax return, there is no reason to amend your tax return.  The IRS is taking 6 months or longer to process amended tax returns and the Advance CTC being issue during calendar year 2021 ends permanently after December 15, 2021.

If you have eligible dependents for a Child Tax Credit you will be entering them on your 2021 tax return to be filed next year in 2022.  If you had a child born in 2021 that child cannot be entered on a 2020 tax return and can only be entered on a 2021 tax return next year.