https://www.irs.gov/coronavirus/economic-impact-payments
To help everyone check on the status of their payments, the IRS is building a second new tool expected to be available for use by April 17. Get My Payment will provide people with the status of their payment, including the date their payment is scheduled to be deposited into their bank account or mailed to them.
An additional feature on Get My Payment will allow eligible people a chance to provide their bank account information so they can receive their payment more quickly rather than waiting for a paper check. This feature will be unavailable if the Economic Impact Payment has already been scheduled for delivery.
Have you file a 2018 or 2019 tax return and did you enter direct deposit information that is still correct on the tax return? If so, you will get your check direct deposited into that same account.
If you have not filed a return and don't need to, use this web site to register for the payment with direct deposit information: https://turbotax.intuit.com/stimulus-check/
If you filed a return but there was no direct deposit information on it or the bank account information has changed, then you need to enter the correct information on an IRS online portal when it is available around mid April. See this from the IRS: https://www.irs.gov/coronavirus/economic-impact-payments