Configures voice call-based two-factor authentication. At login the user receives an automated phone call that reads out a one-time passcode.

Settings
Code Length
The number of digits in the spoken one-time code. Range 4–16. Default is 6.
Hello Message
An optional greeting played at the start of the call before the code is read out (max 64 characters). Example: Hello, this is a security verification call from Acme Corp.
Repeatable Message
The message that reads out the authentication code. Use the placeholder [code] where the digits should be spoken (max 128 characters). Default: Your authentication code is [code].
Hangup Message
An optional message played before the call ends (max 64 characters). Example: Thank you. Goodbye.