**SendTransactionalWithFallback** function sends transactional email, push and sms messages with fallback to recipients. In case fallbackChannel parameter is not entered, only the specified channels will be sent.
In case fallbackChannel parameter is specified, the request for the entered value must be filled. emailRequest **(optional)** : payload is like [**here**](https://dev.dengage.com/reference/sendtransactionalemail).
pushRequest **(optional)** : payload is like [**here**](https://dev.dengage.com/reference/sendtransactionalpush).
smsRequest **(optional)** : payload is like [**here**](https://dev.dengage.com/reference/sendtransactionalsms).
fallbackChannel **(optional)** : values can be **Email** or **Push** or **Sms**. **Here are some scenario examples;** **Scenario-1**
Send email and push, if they are bounced send sms. In this scenario emailRequest, pushRequest and smsRequest should be filled and fallbackChannel specified as "Sms". ----- **Scenario-2**
Send email and sms, if they are bounced send push. In this scenario emailRequest, pushRequest and smsRequest should be filled and fallbackChannel specified as "Push". ----- **Scenario-3**
Send push, if there is bounced send sms. In this scenario pushRequest and smsRequest should be filled and fallbackChannel specified as Sms. ----- **Scenario-4**
Send push, if there is bounced send email. In this scenario pushRequest and emailRequest should be filled and fallbackChannel specified as "Email". ----- **Scenario-5**
Send sms, if there is bounced send email. In this scenario emailRequest and smsRequest should be filled and fallbackChannel specified as "Email". ----- **Scenario-6**
Send email, push and sms. In this scenario emailRequest, pushRequest and smsRequest should be filled and fallbackChannel should be empty. ----- **Idempotency Support:** This endpoint supports idempotency via the optional traceId parameter. For more information, see [**Rest API Idempotency**](https://dev.dengage.com/reference/rest-api-idempotency). ----- **Scenario-7**
Send email and sms. In this scenario emailRequest and smsRequest should be filled and fallbackChannel should be empty. ----- **Scenario-8**
Send email. In this scenario emailRequest should be filled and fallbackChannel should be empty. ----- **Scenario-9**
Send push. In this scenario pushRequest should be filled and fallbackChannel should be empty. ----- **Scenario-10**
Send sms. In this scenario smsRequest should be filled and fallbackChannel should be empty.

200The operation is successful and the content has been deleted.

400Bad request, occurs when the contentId is missing or has an invalid format.

403The operation is not allowed. Your API user is not authorized to use this API.

404The SMS content with the specified contentId was not found.

500Unexpected error occurred on the server.