How to use Bitwarden Authenticator
Note: Bitwarden Authenticator is only available for Premium accounts and accounts associated with an Organization.
Bitwarden Authenticator allows you to generate TOTP codes for two-step login right within your Bitwarden login items. Generating TOTP codes with Bitwarden Authenticator gives you the convenience of sharing TOTP codes with colleagues (ex. if you have a shared login) as well as being able to use them as part of auto-fill.

Mobile Apps
When using a Bitwarden mobile app, you can use your phone's camera to scan the QR code shown when setting up your TOTP on a given website.

Desktop Clients
When using a Bitwarden desktop client (ex. Desktop app, Browser extension, or Web app), you will need to add the authenticator key manually in order to generate your TOTP codes. Typically, you will have an option to view the text of the authenticator key or secret just below the QR code.

Once Bitwarden is generating your TOTP code for that particular site, you will be able to go to the site's login screen and use one of the Bitwarden auto-fill options to fill in your username and password. The website will then ask for the TOTP code.
Simply click into the field and paste with Ctrl/Cmd + V