# Ask: OTP verification

{% hint style="info" %}
This feature is only available from Base Flows skill 3.7
{% endhint %}

When working with phone numbers, you need to be able to verify if the phone number is actually owned by the user. For this you can use the Ask OTP verification node variant. It will send an SMS to the number with a number in it. Then it will ask the user to pronounce the number, or when DTMF only is toggled, type in the number finished by the hash key. This way, the user proves he or she owns the number.

<figure><img src="https://3356808761-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FEBQHGJABNTj5ISSOTRxM%2Fuploads%2FCywM5G3Tl8af341xZCqv%2Fimage.png?alt=media&#x26;token=19f24948-23a9-4e17-ad8f-ea4049485f82" alt=""><figcaption></figcaption></figure>

{% hint style="info" %}
Make sure to select "mobile phone number" in the Phone number type field in the [Ask Phone node](https://manuals.dialox.ai/studio/flows/nodes/ask-phone), because the SMS will only arrive on devices that can actually receive SMS messages
{% endhint %}

### Node properties

| Property            | Description                                                                            | Explanation                                                                                                                                                                       |
| ------------------- | -------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Question            | The original question                                                                  |                                                                                                                                                                                   |
| Try again (1)       | The repeat question when wrong input is provided                                       | optional                                                                                                                                                                          |
| Try again (2)       | An alternative repeat question when wrong input is provided                            | optional                                                                                                                                                                          |
| Assign to           | To assign the result to a variable in the conversation                                 |                                                                                                                                                                                   |
| Remember            | To also store the variable in the user object                                          | The variable name in the Assign to will be used to store the value in the user object.                                                                                            |
| Record audio ☎      | On phone channels there is an option to record the audio                               |                                                                                                                                                                                   |
| Assign audio URL to | When record audio is toggled the URL to the audio file will be stored in this variable | When record audio is toggled the URL to the audio file will be stored in this variable                                                                                            |
| SMS text            | The text to use for sending the SMS.                                                   | You can interpolate the `otp_code` in there by using the / command. Make sure to [add a variable](https://manuals.dialox.ai/studio/flows/variables) with exactly this name first. |
| Sent message        | The text the bot will use to announce the sending of the SMS                           |                                                                                                                                                                                   |
| Resent message      | The text the bot will use to announce a retry of the SMS sending                       | This happens when the user would, instead of providing a code, indicate he or she didn't receive the SMS message.                                                                 |