If you have filed your return and it is in pending status, wait until it's either accepted or rejected. If it has been accepted, it's too late to change your bank account information. If it happens to get rejected, you can update your bank account before re-submitting your return as well as update the issue that caused the rejection.
If the information you provided is for a closed or invalid bank account, or if your bank rejects your direct deposit, the IRS will mail you a check.
Please see the following TurboTax FAQ for assistance with updating your bank account before filing. https://ttlc.intuit.com/replies/4083015
This TurboTax FAQ explains what to do after you filed and need to update your bank information.