You cannot change the banking information for a refund after you file your tax return. The next time you can change the information will be when you are ready to file your 2020 return. Then you can change it in the FILE section for your 2020 refund. That information will not go from TurboTax to the IRS until you file your 2020 return.
If the IRS has a wrong or closed account for your 2019 refund, the refund will go back to the IRS and then they will mail a check to the address on your tax return.