To get started, go to your Dropbox account’s security page and Enable two-step verification – the setting is available right at the bottom of the page. Now follow the wizard to associate your phone (or phone number) with the security option. Dropbox will also provide an emergency backup code that you should print and keep at a secure place – this will be required if you ever lose your mobile phone and need to get into Dropbox sidestepping the security settings.
