The increased Child Tax Credit is only for tax year 2021 which is filed next year, not for tax year 2020.
Any advances on the credit in 2020 will be handled by the IRS.
See this TurboTax support FAQ for information on the American Rescue Plan - https://ttlc.intuit.com/community/tax-topics/help/how-will-the-stimulus-package-impact-me/00/1393859
