Now you can use multi DTMF (dual-tone multi-frequency signalling) with Flow Builder. 

Also known as 'touchtone' phone, multi DTMF is the signal that you generate when you press an ordinary telephone's touch keys.

Multi DTMF is the response code that is generated when the end user presses the telephone's keys. Each key pressed is uniquely identified with multi DTMF code which is received and interpreted, enabling the reception and verification of information from the end user. For example, DTMF behaviour happens when you enter your PIN code during a voice call.

Using multi DTMF in Flow Builder

1. Add a 'Say' step, and set-up your variables. Click on save when ready. 

2. Whenever you add a 'Say' step, you'll see the icon of multi DTMF on the right. 

Click on it for the Multi key input menu to be displayed. Here you'll be able to set up the input conditions:

• Max. input length: Select this option if you want to set up a maximum number of characters that the user can enter. In the example below, the PIN has 4 digits. When the user finishes pressing 4 digits, the input will start to be verified.
• End key: Select this option if you want the user to press a specific key to indicate that they finished. You can select which key do you want them to press by clicking on the drop-down menu; for this example will be #.

* You can select both maximum input length and end key, or just one or the other.

• Input variable name: It's important that you name your variable for multi DTMF to work correctly. In this example, the name will be key_input.

3. Add a 'Branch' step and set-up your variables.

Since multi DTMF behaviour is useful to verify information from the end user, you'll always need to add a 'Branch' step after.

• If the code is correct, the user can go on in the flow. In our example, 1234 is the correct code.
• If the code is incorrect, the user needs to press the keys again.

• In this example, if the code is correct, the user is forwarded to the department that will set-up whatever the user needs.

• If the code is incorrect, the user needs to press the keys again.

The final flow using multi DTMF behaviour for this example would look like this: