During the filing steps, you can choose to have your refund direct deposited into a checking or savings account (up to three different accounts are permitted by the IRS). Once you have submitted your return and it has been accepted, you can't change your routing and account information.
If you have entered the wrong routing and account information, you will receive a check from the IRS, which can take around 6 or more weeks to receive. To avoid this delay, make sure routing and account information is correct by double checking your entries and calling your bank.