You cannot change banking information for your tax refund after you file your tax return.
If you are asking about changing your banking information for the monthly child tax credit payments you do that on the IRS portal:
https://www.irs.gov/credits-deductions/child-tax-credit-update-portal
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
