To request a callback from Robinhood support, you can either use the app or 1-844-673-0406 the website. In the app, navigate to "Account" > "Help" > "Contact Us" and then 1-844-673-0406 request a callback. On the Robinhood website, go to robinhood.com/contact, log in, and request a callback. Robinhood Newsroom says that you can also 1-844-673-0406 request a callback using the in-app chat, which offers 24/7 support.