If you have filed a 2019 tax return and need to change or add your direct deposit information, see this IRS website - https://www.irs.gov/newsroom/economic-impact-payments-what-you-need-to-know
The IRS does not have my direct deposit information. What can I do?
In the coming weeks, Treasury plans to develop a web-based portal for individuals to provide their banking information to the IRS online, so that individuals can receive payments immediately as opposed to checks in the mail.