send-phone-message trigger runs when using SMS/Voice as a factor for Multi-factor Authentication (MFA). It runs for both the enrollment process and the challenge process (event.message_options.action), and for the voice message type when using the New experience for (event.message_options.message_type === 'voice'). When using a custom provider to send the messages, this trigger is required to configure your custom provider.

References
- Event object: Provides contextual information about the message to be sent and the user to be challenged or enrolled.
- API object: Provides methods for changing the behavior of the flow.
Common use cases
Use a custom SMS provider
A send-phone-message Action can be used to deliver MFA messages through a custom SMS provider:For this Action to execute properly, the Action must contain secrets named
AWS_REGION, AWS_ACCESS_KEY_ID, and AWS_SECRET_ACCESS_KEY, and must have a dependency on the aws-sdk npm package.