If you need to amend your 2022 tax return that you prepared in TurboTax Online, follow the instructions in the following TurboTax Help Article:
As mentioned in the article, make sure you really need to amend, which means make sure you are eligible for the Child Tax Credit before amending.
For additional information, including eligibility requirements for the Child Tax Credit, see the following TurboTax Help Article:
What is the Child Tax Credit? Note - Although the Help article is for 2023, the requirements for the credit are the same as 2022.