We recommend using an authenticator app for increased security without the need of sending text messages.
Receiving codes via SMS is less secure than using an authentication app. A hacker could intercept a text message or hijack your phone number by convincing your carrier to transfer it to another device. Or if you sync text messages with your computer, a hacker could gain access to SMS codes by stealing your computer.
Once you have set up an authenticator app, you will have to verify your first login every 12 hours.