When you are ready to e-file, you can add your banking information if you want to receive your refund by direct deposit.
You have to go to Step 2 in the FILE section.
HOW TO CHANGE OR ENTER BANKING INFORMATION FOR REFUND
https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-refund/change-transferred-direct-deposit-information/L77NCbU6D_US_en_US?uid=m6tuh572
You cannot change banking information while your return is in pending, nor can you change it after the return is accepted. The IRS does not allow it.