General 

The goal of this feature is to allow the implementer to set DTMF tones when transferring a call to an external number. This means that the call will be transferred without user action by the flow using the "Pass To Address" activity and after it is connected, the configured tones will be sent to the remote address.

One possible real world scenario: customer is directed by the flow to an external system that use IVR and request the customer to send data for example user identifier, credit card number, access code, etc... 
In this case if we already have this information in hand, we can set the activity to transfer the interaction to the remote number and also send the DTMF data on behalf of the customer 

Another simple solution can be simple navigating the first step of the remote IVR 

Implementation 

On "Pass To Address" activity we have new options for selecting 2 additional parameters, the first is the delay that we need to wait from the time the call is connected until we start sending the DTMF sequence (one or numerous digits can be sent)
The second parameter is the sequence itself 

Important!!!

This feature is limited for a single action, there is no option to create a whole scenario of waiting and sending digits. 

If customers requires more complicated scenarios, it should be developed separately