# whatsapp.calling_prerequisites_missing

> The whatsapp.calling_prerequisites_missing Problem Details code: Calling cannot be turned on until the number is subscribed to call webhooks.

Source: https://docs.nexafone.so/v1/errors/whatsapp.calling_prerequisites_missing/

| | |
| --- | --- |
| HTTP status | `422` |
| Area | WhatsApp (from Meta) |
| Problem `type` | `https://docs.nexafone.so/errors/whatsapp.calling_prerequisites_missing` |

## What the `detail` says

The `detail` explains the occurrence; it can read, for example:

- Calling cannot be turned on until the number is subscribed to call webhooks.

## Handling it

The request is well-formed but its values are not accepted; fix them before retrying.

## Example

```json
{
  "type": "https://docs.nexafone.so/errors/whatsapp.calling_prerequisites_missing",
  "title": "Unprocessable Entity",
  "status": 422,
  "code": "whatsapp.calling_prerequisites_missing",
  "detail": "Calling cannot be turned on until the number is subscribed to call webhooks.",
  "requestId": "01J9Z8Q4TQ3W6M5V2X7Y8Z9A0B"
}
```

Match on `code`, never on `detail`: the wording may change. See [Problem Details](/v1/errors/).