If you filed a 2018 or 2019 federal tax return with direct deposit information on it and the refund was sent directly to your bank rather than to the 3rd party refund processing service that takes your TurboTax fees out of your refund and the bank information has not changed, then you don't need to do anything for the IRS to direct deposit the stimulus payment to your account.
If you had your TurboTax fees paid from your federal refund, there is some confusion about how the IRS will handle your stimulus payment.
An IRS online portal will open up about mid April where you can check the status of your stimulus payment: https://www.irs.gov/coronavirus/economic-impact-payments
