If you filed a 2018 or 2019 federal tax return with a federal tax refund and selected Direct Deposit for the tax refund then the IRS has your direct deposit information. It does not matter if you selected the Direct Deposit to a bank account or to a debit card, the routing and account number is used for Direct Deposit.
Use this IRS website for stimulus payment status or to update your bank account - https://www.irs.gov/coronavirus/economic-impact-payments
